• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.9
• /
• pp.5756-5762
• /
• 2015

This paper has studied the lotus effect of the biomimetic engineering that is inspired from the nature. The biomimetic engineering has been improved with the nanotechnology. This paper has observed the hydrophobic property of the surface of the lotus leaf by using the scanning electron microscope (SEM) and atomic force microscope (AFM). The nano-scale of the hydrophobic lotus leaves are maximized the surface tension of water. The general grass leaf has been compared with the lotus leaf through the SEM and AFM - in the viewpoint of the 2D and 3D morphology. Also, The pre-existing of the hydrophobic theory was investigated and compared with the experimental observations for the lotus leaf.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.124.2-124.2
• /
• 2010

Generally, a coolant of the nuclear power plant is manufactured by electrolyzing the sea water near the plant for making the sodium hypochlorite(NaOCl), which is used for sterilizing the bacteria and the shellfishes sticking to the drains or the pumps at the outlet of the cooling system due to $8-10^{\circ}C$ warmer temperature than the inlet sea water. During manufacturing the sodium hypochlorite, the hydrogen with the high purity is also produced at the anode side of the electrolyzer. This paper describes a novel power plant system combined with the polymer electrolyte membrane(PEM) fuel cell, the wasted hydrogen from the sea water electrolyzer and the wasted heat of the nuclear power plant. The present status over the exhausted hydrogen at twenty nuclear power plants in Korea was investigated in this study, from which an available power generation is estimated. Furthermore, the economic feasibility of the PEM fuel cell power plant is also evaluated by a current regulations over the power production and exchange using a renewable energy shown in Korea Power Exchange(KRX).

• Journal of Drive and Control
• /
• v.16 no.4
• /
• pp.93-100
• /
• 2019

Nuclear and thermal power plants must provide the turbines with an appropriate degree of high temperature and high pressure steam, to produce the optimum electricity. Additionally, in the event of system and power system failure during electrical production, the steam is immediately disabled, to protect the turbines and generators rotating at high speed. The plant thus uses a special steam control valve system for turbine control, which is opened by force of the hydraulic servo actuator and closed by a large steel spring force. In this study, the causes of failure of the turbine control valve system, a key device of the power plants, were analyzed, and the causes of failure were improved relative to reliability of the equipment.

• Proceedings of the KAIS Fall Conference
• /
• 2011.05a
• /
• pp.85-88
• /
• 2011

석유 등 화석연료로 인한 지구온난화 문제와 더불어 일본 대지진 이후 원자력발전의 안전에 의문이 제기 되면서 신재생에너지에 대한 관심이 한층 고조되고 있다. 이에 발맞추어 국가정책으로 녹색성장 정책이 실행됨에 따라 2030년까지 전체 에너지원 중 신에너지전원의 비중을 전체 에너지원의 11%로 확대하는 정책을 적극적으로 추진하고 있다. 따라서 신재생에너지를 통하여 얻은 전기에너지를 저장하여 사용 할 수 있는 2차 전지에 대한 연구가 다수의 산업 현장에서 각광을 받고 있다. 최근 2차 전지는 Smart Grid 및 전기자동차분야에서 폭넓게 사용 되면서 정확한 출력전압, SOC 및 충-방전 예상 시간을 추정하여 2차 전지의 과충전, 과방전으로 인하여 생기는 고장 및 사고를 미연에 방지하고 2차 전지 사용 시 편의성을 제공하기 위한 시스템에 대한 연구가 필요한 실정이다. 본 논문은 이런 실정에 맞추어 LabVIEW 프로그램을 활용하여 2차 전지의 상태를 실시간으로 감시 및 제어하는 프로그램을 제작함으로써, 사고 시 2차 전지에 가해지는 피해 방지 및 관리 시 발생하는 여러 문제점에 대한 효율적인 해결 방안을 제시하고자 한다.

• Proceedings of the KIEE Conference
• /
• 2002.07d
• /
• pp.2733-2735
• /
• 2002

본 논문에서는 원자력 발전소용 이더넷 기반 링형 실시간 제어 통신망인 ERCNet(Ethernet-based Real-Time Control Network)에서 고신뢰성을 유지하기 위한 결함 허용 방법들을 제시한다. 임의의 노드의 프로그램 동작에 이상(fault)이 발생하였을 경우, 와치독(Watchdog) 타이머로 탐지하여 링을 자동 복구하고, 그 노드가 다시 회복될 경우의 노드 추가 메커니즘을 제안한다. 이 메커니즘은 한 노드가 전체 네트워크에서 제외되거나 추가될지라도 네트워크가 운용성(operability)을 유지할 수 있도록 한다. 두 번째로, 한 채널 또는 양 채널 에러 발생시 이 에러를 대처하기 위한 채널 이중화 방식과 시스템 이중화 방식에 대해 제안한다. 마지막으로 통신망의 임의의 위치에서 이상이 발생했을 경우 그 발생 위치를 파악할 수 있는 메커니즘을 제안한다.

• Korean Chemical Engineering Research
• /
• v.52 no.3
• /
• pp.279-288
• /
• 2014

Nuclear energy is expected to meet the growing energy demand while avoiding CO2 emission. However, the problem of accumulating spent fuel from current nuclear power plants which is mainly composed of uranium oxides should be addressed. One of the most practical solutions is to reduce the spent oxide fuel and recycle it. Next-generation fuel cycles demand innovative features such as a reduction of the environmental load, improved safety, efficient recycling of resources, and feasible economics. Pyroprocessing based on molten salt electrolysis is one of the key technologies for reducing the amount of spent nuclear fuel and destroying toxic waste products, such as the long-life fission products. The oxide reduction process based on the electrochemical reduction in a LiCl-$Li_2O$ electrolyte has been developed for the volume reduction of PWR (Pressurized Water Reactor) spent fuels and for providing metal feeds for the electrorefining process. To speed up the electrochemical reduction process, the influences of the feed form for the cathode and the type of anode shroud on the reduction rate were investigated.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.9 no.6 s.46
• /
• pp.13-19
• /
• 2005

Floor response spectra for dynamic response of subsystem such as equipment, or piping in nuclear power plants are usually generated without considering dynamic interaction between main structure and subsystem. This study describes the analytic method in which equipment response spectra can be obtained through dynamic analysis considering equipment-structure Interaction(ESI). In this method, dynamic response of the equipment by this method is based on a dynamic substructure method in which the equipment-structure system is partitioned into the single-degree-ol-freedom system(SDOF) representing the equipment and the equipment support impedance representing the dynamic charactenstics of the structure ai the equipment support. A family of equipment response spectra is developed by applying this method to calculate the maximum responses of a family of SDOF equipment systems with wide banded equipment frequency, damping ratio, and mass. The method is validated by comparing the floor response spectrum from this method with the floor response spectrum generated from the rigorous analysis including equipments on the containment building of a prototypical nuclear power plant. in order to Investigate ESI effect in the response of equipment, response values from the method and the conventional approach without considering ESI are compared for the equipment having the mass less than 1% of the total structural mass. Response spectra from the method showed lower spectral amplitudes than those of the conventional floor response spectra around controlling frequencies.

• Tunnel and Underground Space
• /
• v.34 no.1
• /
• pp.28-53
• /
• 2024

In general, high-level radioactive waste (HLW) generated as a result of nuclear power generation should be disposed within the country. Determination of the disposal site and host rock for HLW deep geological repository is an important issue not only scientifically but also politically, economically, and socially. Considered host rock types worldwide for geological disposal include crystalline rocks, sedimentary rocks, volcanic rocks, and salt dome. However, South Korea consists of various rock types except salt dome. This paper not only analyzed the geological and rock mechanical characteristics on a nationwide scale with the preliminary results on various rock type studies for the disposal host rock, but also reviewed the characteristics and possibility of various rock types as a host rock through deep drilling surveys. Based on the nationwide screening for host rock types resulted from literature review, rock distributions, and detailed case studies, Jurassic granites and Cretaceous sedimentary rocks (Jinju and Jindong formations) were derived as a possible candidate host rock types for the geological disposal. However, since the analyzed data for candidate rock types from this study is not enough, it is suggested that the disposal rock type should be carefully determined from additional and detailed analysis on disposal depth, regional characteristics, multidisciplinary investigations, etc.

• Fire Science and Engineering
• /
• v.32 no.1
• /
• pp.89-98
• /
• 2018

Fire accidents in foreign countries, like the accident in a thermal power plant in Beijing, the accidents in domestic power plants, including Boryeong Power Plant in 2012 and Taean Power Plant in 2016, a disaster in a nuclear power plant in Fukushima in 2011 or the large-scale power failure in California in 2001 are safety accidents related to electric power, which caused losses in the people's stable lives and the countries. Electricity has an absolute impact on the people's life and the economy, so we can easily expect the serious situation affecting economic growth as well as direct damage to the protection of the people's lives and the losses of properties, if there are fire or explosion accidents or radioactive leak because of negligence in safety management, or problems because of natural disasters like an earthquake in power plants that generate electricity. In this study, it was drawn the improvement of the organizations exclusively in charge of firefighting, the operation of a program for the improvement of professional competency, the development of a customized firefighting management system for plants for systematic firefighting safety management and the improvement of the earthquake-proof correspondence system, which has recently become an issue, as measures for improvements through a survey of the actual conditions concerning the necessity of the construction of a firefighting safety management system for power plants with five power generation companies, including Korea Southern Power Co., Ltd., and the persons in charge of firefighting safety Korea Hydro & Nuclear Power Co., Ltd.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.33 no.1
• /
• pp.26-33
• /
• 2013

BMI nozzles in bottom head of the nuclear vessel are one of major components in nuclear power plants. The BMI nozzles have high possibility to generate PWSCC(primary water stress corrosion crack) according to recent foreign case although operation temperature is lower then the upper head of the nuclear vessel. Thus, nondestructive inspection of the BMI nozzles is required. But, inspection of BMI nozzles is not easy since the BMI nozzles placed in high radiated area and inside the nozzles filled with boric acid. Thus, in this study, a TOFD transducer for inspection of BMI and automated scanner system with water were developed. Also, validation of performance of the developed transducer and system are performed using specimens with artificial defects.