• Journal of Mechanical Science and Technology
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• 제17권7호
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• pp.947-957
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• 2003

The pressure tube is a major component of the CANDU reactor, which supports nuclear fuel bundle. In order to complete the integrity evaluation of pressure tube, expert knowledge, iterative calculation procedures and a lot of input data are required. More over, results of integrity assessment may be different according to the evaluation method. For this reason, an integrity evaluation system, which provides efficient way of evaluation with the help of attached database, was developed. The present system was built on the basis of 3D FEM results, ASME Sec. XI, and Fitness For Service Guidelines for CANDU pressure tubes issued by the AECL (Atomic Energy Canada Limited). The present system also covers the delayed hydride cracking and the blister evaluation, which are the characteristics of pressure tube integrity evaluation. In order to verify the present system, several case studies have been performed and the results were compared with those from AECL. A good agreement was observed between those two results.

• 대한기계학회논문집A
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• 제20권2호
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• pp.575-584
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• 1996

The objective of this paper is to develop an expert system for nuclear piping integrity. This paper describes the selection methodology of integrity evalution method and the inference of material properties. To select the integrity evaluation method, the weight factor for respective material properties was obtained by the sensitivity analysis of the effect of material properties on integrity evaluation method. Subsequently the possession ratio for respective integrity evaluation method was computed, and the most appropriate integrity evaluation method for given input information is selected. In the material properties inference, stress-strain curves and J-R curves were predicted from tensile properties such as yield strength and tensile strength.

• 한국CDE학회논문집
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• 제6권2호
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• pp.140-146
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• 2001

A nuclear Power Plant is composed of a number of mechanical components. Maintaining the integrity of these components is one of the most critical issues in nuclear industry. In order to evaluate the integrity of these mechanical components, a lot of data are required including inspection data, geometrical data, material properties, etc. Therefore, an effective database system is essential to manage the integrity of nuclear power plant. For this purpose, an internet based virtual reality environment and web database system was proposed. The developed virtual reality environment provides realistic geometrical configurations of mechanical components using VRML (Virtual Reality Modeling Language). The virtual reality environment was linked with the web database, which can manage the required data for the integrity evaluation. The proposed system is able to share the information regarding the integrity evaluation through internet, and thus, will be suitable for an integrated system for the maintenance of mechanical components.

• 대한기계학회논문집A
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• 제24권8호
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• pp.2083-2090
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• 2000

In order to manage nuclear power plants safely and cost effectively, it is necessary to develop integrity evaluation methodologies for the main components. Recently, the integrity evaluation techniques were broadly studied regarding the license renewal of nuclear power plants which were approaching their design lives. Since the integrity evaluation process requires special knowledges and complicated calculation procedures, it has been allowed only to experts in the specified area. In this paper, an integrity evaluation system for reactor pressure vessel was developed. RVIES(Reactor Vessel Integrity Evaluation System) provides four specific integrity evaluation procedures covering PTS(Pressurized Thermal Shock) analysis, P-T(Pressure-Temperature) limit curve generation, USE(Upper Shelf Energy) analysis and Fatigue analysis. Each module was verified by comparing with published results.

• 한국생산제조학회지
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• 제26권4호
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• pp.436-440
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• 2017

This study evaluated the design and structural integrity of a three-axle bogie frame in a railway freight car through a numerical analysis and an experimental evaluation. A three-axle bogie frame, which supports the weight of the car body and load, is required to transport heavier cargo because two-axle vehicles have structural limitations. Therefore, this study performed a structural analysis and static load tests to evaluate the design and structural integrity of a three-axle bogie frame. The results obtained from the numerical analysis were compared to those of the experiments. For the bogie frame used in the experiments, a failure evaluation was performed using non-destructive methods. The numerical analysis and experimental evaluation were satisfactory for the structural integrity evaluation.

• 방사성폐기물학회지
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• 제19권3호
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• pp.307-322
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• 2021

This study developed an analytical methodology for the mechanical integrity of spent nuclear fuel (SNF) cladding tubes under external pinch loads during transportation, with reference to the failure mode specified in the relevant guidelines. Special consideration was given to the degraded characteristics of SNF during dry storage, including oxide and hydride contents and orientations. The developed framework reflected a composite cladding model of elastic and plastic analysis approaches and correlation equations related to the mechanical parameters. The established models were employed for modeling the finite elements by coding their physical behaviors. A mechanical integrity evaluation of 14 × 14 PWR SNF was performed using this system. To ensure that the damage criteria met the applicable legal requirements, stress-strain analysis results were separated into elastic and plastic regions with the concept of strain energy, considering both normal and hypothetical accident conditions. Probabilistic procedures using Monte Carlo simulations and reliability evaluations were included. The evaluation results showed no probability of damage under the normal conditions, whereas there were small but considerably low probabilities under accident conditions. These results indicate that the proposed approach is a reliable predictor of SNF mechanical integrity.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.160-165
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• 2004

An effective integrity evaluation system is essential to manage the fitness for service issues on infra-structure because the evaluation processes usually take long times and are detrimental for productivity point of view. In this paper, the key structures and procedures of four integrity evaluation programs which have been developed based on currently available codes and standards are described. The proposed programs are not only flexible to adopt advances in fitness for purpose type assessment methodologies but also convenient for field engineers. The developed programs which will be unified as an integrity evaluation system are expected to play a prominent role for integrity evaluation of major infra-structure.

• 대한기계학회논문집A
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• 제28권6호
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• pp.663-669
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• 2004

A nuclear power plant is composed of a number of primary components. Maintaining the integrity of these components is one of the most critical issues in nuclear industry. In order to maintain the integrity of these primary components, a complicated procedure is required including regular in-service inspection, failure assessment, fracture mechanics analysis, etc. Also, experts in different fields have to co-operate to resolve the integrity issues on the basis of inspection results. This integrity evaluation process usually takes long, and thus, is detrimental for the plant productivity. Therefore, an effective safety evaluation system is essential to manage the integrity issues on a nuclear power plant. In this paper, a web-based fatigue life evaluation system for primary components in nuclear power plant is proposed. This system provides engineering knowledge-based information and concurrent and collaborative working environment through internet, and thus, is expected to raise the efficiency of integrity evaluation procedures on primary components of a nuclear power plant.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.3059-3066
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• 2008

It is reported that the life of generator stator windings is expected about 30 years and a leak and water absorption phenomena can be progressed by fatigue, vibration, and corrosion. The water-cooled generator stator windings which were operated over 15 years are over 20 units and the mechanical problems such as leak and water absorption were found in the generator stator windings. In this paper, the systematic mechanical integrity evaluation methods which are applied to the water-cooled generator stator windings within the country are introduced.

• 대한기계학회논문집A
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• 제25권7호
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• pp.1031-1038
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• 2001

In order to verify the analytical methods predicting failure behavior of cracked piping, full-scale pipe tests are crucial in nuclear power plant piping. For this reason, series of international test programs have been conducted. However, full-scale pipe tests require expensive testing equipment and long period of testing time. The objective of this paper is to develop a test system which can economically simulate the full-scale pipe test regarding the integrity evaluation. This system provides the failure behavior of cracked pipe by testing a wide-plate specimen. The system provides the failure behavior of cracked pipe by testing a wide-plate specimen. The system was developed for the integrity evaluation of nuclear piping based on the methodology of hardware-in-the-loop (HiL) simulation. Using this simulator, the piping integrity can be evaluated based on the elastic-plastic behavior of full-scale pipe, and the high cost full-scale pipe test may be replaced with this economical system.