• Nuclear Engineering and Technology
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• v.55 no.1
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• pp.169-179
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• 2023

Filtered containment system is a passive safety system that controls the over-pressurization of containment in case of a design-based accidents by venting high pressure gaseous mixture, consisting of air, steam and radioactive particulate and gases like iodine, via a scrubbing system. An indigenous lab scale facility was developed for research on iodine removal by venturi scrubber by simulating the accidental scenario. A mixture of 0.2 % sodium thiosulphate and 0.5 % sodium hydroxide, was used in scrubbing column. A modified mathematical model was presented for iodine removal in venturi scrubber. Improvement in model was made by addition of important parameters like jet penetration length, bubble rise velocity and gas holdup which were not considered previously. Experiments were performed by varying hydrodynamic parameters like liquid level height and gas flow rates to see their effect on removal efficiency of iodine. Gas holdup was also measured for various liquid level heights and gas flowrates. Removal efficiency increased with increase in liquid level height and gas flowrate up to an optimum point beyond that efficiency was decreased. Experimental results of removal efficiency were compared with the predicted results, and they were found to be in good agreement. Maximum removal efficiency of 99.8% was obtained.

• 한국가스학회:학술대회논문집
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• 2001.10a
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• pp.114-121
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• 2001

• Journal of Advanced Research in Ocean Engineering
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• v.3 no.3
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• pp.112-124
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• 2017

As an LNG carrier preserves and transports liquefied natural gas under minus $163^{\circ}C$, the cargo tank has to have sufficient hull strength against not only the wave loads but also against loads caused by loading and unloading and thermal expansion to keep the LNG safely. The main insulation types for a CCS are No.96 and Mark III from GTT for the membrane LNG carrier. Particularly, the invar membrane plate in No.96 is very thin and its connections could experience high local stresses owing to such dynamic loads. Therefore, it should be verified whether those connections have sufficient fatigue lives for the purpose of operation and maintenance. This research aims at performing fatigue analysis with 0.1 fatigue damage criteria for 40 years of design life to support new membrane CCS development using proper S-N curves and the associated finite element modeling technique for each connection and then propose a reasonable design methodology.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.539-543
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• 2011

LNG cargo containment system (CCS) has the primary function of ensuring adequate thermal insulation with keeping natural gas below its boiling point. From the viewpoint of structural design, this LNG CCS can be treated as a laminated composite structure showing complex structural responses under the sloshing load which can be defined as a violent behavior of the liquid contents in cargo tanks due to external forced motions. As LNG CCS type, Mark III containment system from TGZ is considered in this paper and then its structural strength assessment is performed based on a simple higher-order shear deformation theory and maximum stress, maximum strain, Tsai-Wu failure criteria developed for laminated composite plates. The assessment is performed to the initial failure of the Mark III CS plate by investigating failure locations and loads.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.330-335
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• 2000

Faults detection and containment requirements are typically allocated from a top-level specification as a percentage of total faults detection and containment, weighted by failure rate. This faults detection and containments are called as a fault coverage. The fault coverage requirements are typically allocated identically to all units in the system, without regard to complexity, cost of implementation or failure rate for each units. In this paper a simple methodology and mathematical model to support the allocation of system fault coverage rates to lower-level units by considering the inherent differences in reliability is presented. The models are formed as a form of constrained optimization. The objectives and constraints are modeled as a linear form and this problems are solved by linear programming. It is identified by simulation that the proposed solving methods for these problems are effective to such requirement allocating.

• Korean Journal of Social Welfare
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• v.46
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• pp.349-376
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• 2001

The objectives of this study is to examine the German mandatory prescription system in terms of the applicability and restriction of the pharmaceutical policy in order to obtain some useful implications for solving the problems in Korean prescription system. Recently, in Germany, an issue about the security of the prescription, the price control of the pharmaceuticals and the containment of the increasing prescription expenditure has been intensively discussed. Similar problems are also occurred in Korea. So, the policy measurements of Germany could be used in Korea. But it could not easy to introduce the German policy measurements in Korea because of the social-institutional differences between the two countries, which are following; (1) Korea has a short experience with the mandatory prescription system, (2) the German concept of the management differs from that of the Korea, (3) the subscribers and the patients are excluded from the decision making process, (4) the medical service providers often resist against reform plans. For the stable development of the Korean prescription system the principle of self-government, the collective bargaining concept for cost containment, and social consensus about optimal expenditure of the pharmaceuticals are expected to be needed.

• International Journal of Ocean System Engineering
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• v.1 no.4
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• pp.230-235
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• 2011

Reinforced polyurethane foam (RPUF) is one of the important materials of Mark III type insulation systems used in liquefied natural gas (LNG) cargo containment systems. However, RPUF is the most difficult material to use with regard to its safety assessment, because there is little public and reliable data on its mechanical properties, and even some public data show relatively large differences. In this study, to investigate the structural response of the system under compressive loads such as sloshing action, time-dependent characteristics of RPUF were examined. A series of compressive load tests of the insulation system including RPUF under various temperature conditions was carried out using specimens with rectangular section. As a result, the relationship between deformation of RPUF and time is linear and dependent on the loading rate, so the concept of strain rate could be applied to the analysis of the insulation system. Also, we found that the spring constant tends to converge to a value as the loading rate increases and that the convergence level is dependent on temperature.

• Nuclear Engineering and Technology
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• v.16 no.4
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• pp.217-223
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• 1984

The feasibility of not employing recombiners rather using the postaccident Purge system alone to control hydrogen concentration in the containment following a LOCA, is analyzed in this paper. For this study, the hydrogen concentration in the containment, hydrogen removal through the purge system, and additional off-site dose due to hydrogen purge were calculated. The economic justification of a hydrogen recombiner system (2 recombiners) was also investigated by using the cost benefit concept. As a result, the purge system is sufficient to maintain the hydrogen concentration at a safe level without hydrogen recombiners, and it meets the dose limit requirements set forth in 10 CFR part 100. A hydrogen recombiner system would be justified based on cost-benefit concept for common use in a site with 4 units or more.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.505.1-505
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• 2001

• Proceedings of the Korean Geotechical Society Conference
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• 1998.10a
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• pp.343-350
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• 1998