• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.4
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• pp.57-62
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• 2011

As NPPs' operating times increase, the integrity of nuclear components is continually degraded due to aging effects of systems, structures and components. In addition, for the case of continued operation beyond design life, additional aging effects occurred during the extended operating period lead to more degradation of the integrity of nuclear components. Therefore, it is very important to mange and evaluate the aging to secure the safety of NPPs. Wolsong unit 1 is approaching to its design life of 30 years in 2012. The license renewal documents for continued operation of Wolsong unit 1 Is under reviewing now. In this paper, regulatory technologies for continued operation of Wolsong unit 1 developed by KINS will be introduced. That technologies include the safety review guidelines, regulatory guides for aging management program and regulatory program for audit calculation.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4335-4349
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• 2023

Nuclear marine propulsion has been emerging as a next generation carbon-free power source, for which proper passive residual heat removal systems (PRHRSs) are needed for long-term safety. In particular, the characteristics of unlimited operation time and compact design are crucial in maritime applications due to the difficulties of safety aids and limited space. Accordingly, a compact and long-term-operable PRHRS has been proposed with the key design concept of using both air cooling and seawater cooling in tandem. To confirm its feasibility, this study conducted system design and a transient analysis in an accident scenario. Design results indicate that seawater cooling can considerably reduce the overall system size, and thus the compact and long-term-operable PRHRS can be realized. Regarding the transient analysis, the Multi-dimensional Analysis of Reactor Safety (MARS-KS) code was used to analyze the system behavior under a station blackout condition. Results show that the proposed design can satisfy the design requirements with a sufficient margin: the coolant temperature reached the safe shutdown condition within 36 h, and the maximum cooling rate did not exceed 40 ℃/h. Lastly, it was assessed that both air cooling and seawater cooling are necessary for achieving long-term operation and compact design.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.129-145
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• 2020

The article presents a systematic approach to design of marine navigation channels parameters resulting from manoeuvring and operational safety. Relations between the parameters of waterway system elements and the conditions of safe ship operation have been determined and the objective function of waterway parameters' optimization problems has been minimized with respect to variables of construction and operation costs. These costs have been functionally associated to variables of channel width at the bottom and fairway depth. The method of fairway's width computation at specified safe depth at the preliminary and detailed stages of waterway design has been proposed. The results of this method application have been illustrated with two examples: 1. The modernization of Szczecin-Swinoujscie fairway aimed at accepting vessels of 60,000 DWT capacity. 2. Construction of an approach channel leading to a newly built container terminal in Swinoujscie harbour (Poland), handling ocean-going container ships of 20,000 TEU capacity.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1149-1154
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• 2007

Fluctuation of control rod was experienced when plant was operating in normal operation mode in WH type NPPs. In order to cope with increased control rod fluctuation, the lead-lag controller setpoint for rod control system was optimized and resulted in increasing the margin of operation and minimizing unnecessary control rod movement. By optimization of the time constant, the margin of operation was increased by $1.5^{\circ}F$ and the control rod movement was not occurred due to mitigation of temperature fluctuation in loop. According to the mitigation of time constant, the margin of operation was increased but safety margin can be affected badly, so that the influences to FSAR design reference was evaluated. As the result of this evaluation, it satisfied the design reference of the existing safety analysis and was applied to NPP after obtaining the approval.

• Journal of Ocean Engineering and Technology
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• v.26 no.2
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• pp.1-7
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• 2012

DNV-OS-F101 includes the concept development, design, construction, operation,and abandonment of offshore pipeline systems. The main objective of this offshore standard (OS) is to ensure that pipeline systems are safe during the installation and operational period. The pipeline design philosophy also includes public safety and environmental protection. The mechanical wall thickness design of a pipeline shall follow the design objectives and safety philosophy. This new design code includes a very sophisticated design procedure to ensure a safe pipeline, public safety, and environmental protection. This paper presents the results of a parametric study for the wall thickness design of offshore pipelines. A design matrix was developed to cover the many design factors of pipeline integrity, public safety, and environmental protection. Sensitivity analyses of the various parameters were carried out to identify the impacts on offshore pipeline design.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.2
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• pp.47-52
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• 2003

This study conducted a basic study to develop ISM Code operation evaluation module, which is part of development of Safety Management System(ISM Code) Implementation supporting module. In particular, the significant of this study is that it established AHP operation evaluation analysis process, the design of questionnaire, and the hierarchical structure of operation evaluation model standard, focusing on the development of ISM Code operation evaluation module. Also, this study has its value in the point that it attempted to apply AHP scheme, which is part of the main decision­making in management science field, to develop operation evaluation module.

• Journal of the Korea Safety Management & Science
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• v.14 no.2
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• pp.49-54
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• 2012

As all kind of industry has developed, metal structure and machine instrument use bolt, pin, rivet and welding for assembly and combination. For pin and hinge, dimension accuracy is crucial to keep the operation and safety of the structure and machine instrument. In case of complex machine, the hinge for cover open-loop system is one of the significant design elements. Most of the hinges are being imported and assembled sine they give high technology development cost for its unit cost position. The reason is that the localization of hinge is inadequate. As the demand increase and the necessity of localization grow, it is now more important than ever to develop low cost structure. By the low cost structure, a new technology could be obtained for electronic product and structural hinge since it would enable for complex machine hinge to be guaranteed, technologically. Open-loop hinge is the link type and designed for the structure to keep constant open-loop. And, the hinge is examined in design stability by finite element analysis method. In this paper, the operation result is presented when the hinge for complex machine open-loop is designed for link type structure.

• Journal of Sport and Applied Science
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• v.5 no.1
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• pp.11-15
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• 2021

Purpose: Swimming industry is improving faster than the other types of sport industries and populations of participating swimming are promptly increasing. Lack of recognition of fire safety in swimming facilities is issues related-studies has only recently begun to pay attention. This study is to review and extract fire safety factors for managing swimming pool. Research design, data, and methodology: The study reviewed related-ordinances, governmental documents, and studies discussing safety management of sport facility. Given the literature review, the study produced an initial construct presenting items and factors including fire safety elements and experts' review were conducted to ensure conceptual validity. Finally, the study generated the final factors and subitems representing fire safety elements for swimming pool management. Results: The study confirms factors and elements as follows: the study identifies fire safety equipments as first factors presenting fire extinguisher' place, its proper run, check list and so forth, Second factor is warning system including fire warning equipment, its proper operation, sprinkler and its proper operation, switch and lamp of emergency panel and their proper run and so on. Third factor is evacuation system including a fire exit, exit sign, broadcasting equipment, and their proper operation, and so on. The other factors are an electronic equipment and its subelements, gas management including safety management of LPG, gas valve, pipe, and fire prevention facility including a fire door and its proper operating. Conclusions: Regarding safety management of swimming pool, further discussions and implications were made, and future directions for related-studies were discussed.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.403-414
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• 2003

Periodic safety review on Kori Unit 1 has been successfully done for the first time in Korea. 11 safety factors of the review were fully evaluated in accordance with the domestic legal system. Although it is the oldest nuclear power plant in Korea, Kori Unit 1 was found to have maintained good operating conditions and continuously enhanced its safety by implementing post-TMI action plans and other safety issues, such as replacing steam generators and process/control system. It can be therefore confirmed that safe operation of Kori Unit 1 is guaranteed until next periodic safety review. Nevertheless, some corrective action items were recommended to enhance further its safety level, such as equipment qualification, additional ageing management program, strengthening of some procedures related to administration and human factor. The results of PSR can be utilized for the continued operation beyond the design life as long as the plant safety is maintained and improved. Experiences of the PSR on Kori Unit 1 can be also applied to PSR on other plants.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.9-17
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• 2017

Ensuring the safety of automobiles and trains during system operation is regarded as indispensable due to the progress in unmanned operation. The automotive functional safety standard, ISO 26262, has been proposed to ensure the safe design of vehicles. This standard describes in detail the required risk analysis and evaluation procedure and safety measures, while appropriately reflecting the system design information. Therefore, much research has been done on the risk analysis procedure, wherein the design information is mostly extracted from physical components of similar systems already in operation, the information traced back to obtain constituent functions, and then methods of identifying risk sources are studied. This method allows the sources of risk to be identified quickly and easily, however if the design requirements are changed or systems are newly developed, others may be introduced which are not accounted for, thereby yielding mismatched design information. To resolve this problem, we propose a top-down analysis in order to utilize the system design information appropriately. Specifically, a conceptual system is designed to obtain the functions, which are then analyzed. Then, a function-based fault tree analysis is conducted, followed by a risk source analysis. In this paper, a case study of automotive safety is presented, revealing that the proposed method can analyze the risk sources with reduced possibility of omission by systematically reflecting the system design information.