• 동력기계공학회지
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• 제10권4호
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• pp.71-77
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• 2006

This study introduces the seismic qualification of safety related equipments for nuclear power plants to verify the possibility of resonance in regard to the operating speed and the structural integrity due to external piping nozzle loads as well as seismic dynamic loads using El-Centro earthquake, which was occurred in the 1940's previously. As a first step, it is necessary to investigate the natural frequency of the vertical mixed flow pump in order to determine whether static or dynamic equipment comparing with seismic cut-off frequency, 33hz. Also the normal mode analysis was carried out with the introduction of seismic redesign straint at the middle of vertical pump to increase the natural frequency. In terms of structural integrity, the application of static analysis with normal, upset and faulted nozzle loads event was presented for the comparison of material allowable stress. Also the dynamic analysis was performed to show the design adequacy through the application to the case of El-Centro earthquake.

• 농업과학연구
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• 제48권4호
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• pp.729-738
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• 2021

The purpose of this study was to suggest an improvement plan ultimately to develop practical evaluation methods for national technical qualifications in the field of seeds and horticulture based on the National Competency Standards. Through this, national technical qualifications can be strengthened in terms of professionalism in the seeds and horticulture field. In order to conduct this study, the national technical qualification currently in use was matched to certain competency units and competency unit elements of National Competency Standards. We then visited an industrial site to understand the practical factors related to the technical, facility and equipment aspects of the seeds and horticulture industrial field, after which a practical evaluation exam was developed. Also, for a feasibility study, a pilot test assessment was conducted for students majoring in seeds and horticulture, with a survey also conducted with field experts and an advisory committee consisting of experts in seeds and horticulture. Based on the results, by suggesting an improvement plan for a practical evaluation method leading to better national technical qualifications in the field of seeds and horticulture, it was shown to be possible to improve knowledge, technical, and literacy aspects. This can lead to the training of outstanding technical professionals. Ultimately, the results here are expected to contribute to the improvement of the seeds and horticulture industry.

• Journal of Advanced Marine Engineering and Technology
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• 제40권7호
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• pp.655-662
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• 2016

본 연구에서는 산업 잠수 분야의 현장 책임자 겸 관리 감독자 역할을 할 수 있는 잠수기능장 직책을 국가자격제도로 도입할 것을 제안하였다. 이를 위해 수중전문건설업체 현황, 산업 잠수 장비 운용 실태, 잠수사 근로시간, 인력 수급 현황, 수중전문건설업 시장 현황 등 산업 잠수 분야의 전반적인 현황을 조사하였고, 국가자격체계와 NCS(National Competency Standards) 체계를 분석하여 잠수기능장의 직무 정의와 범위를 도출하였다. 그 결과 산업 잠수 분야의 잠수기능장 자격은 '산업 잠수에 관한 최상급 숙련 기능을 가지고 산업현장에서 공정관리, 소속 기능 인력의 지도 및 감독, 현장교육, 사업주와 기능 인력을 유기적으로 연계시켜주는 현장 관리자로서의 역할을 수행하는 직무'로 정의하고, 잠수기능장의 직무 내용은 '잠수계획수립 및 잠수팀 운영', '표면공급식 공기 혼합기체잠수', '기압조절실 운용', '수중토목', '해난구조' 로 구성하도록 제안하였다. 이 종목이 도입되면 그 동안 관련 분야 종사자들 사이에서 이슈가 되어 왔던 경력 개발을 비롯하여 직급의 관리 감독 등 많은 문제점들을 해소할 수 있을 것으로 기대된다.

• 융합보안논문지
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• 제13권2호
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• pp.75-84
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• 2013

일본은 방범설비협회가 중심이 되어 표준화 문제, 설치기준문제, 자격제도 운영 등을 주도하고 있다. 즉, 이 협회는 기계경비업자, 제조업자, 시공업자 등이 가입하여 방범기기, 방범시스템, 정보시큐리티 시스템에 관한 조사, 연구를 하고 있다. 그리고 방범설비에 종사하는 자의 연수, 방범설비 보급 등을 통해 범죄를 방지하고 국민생활의 안전에 공헌하고 있다. 그리고 방범기기에 대한 연구와 표준화로 방범설비협회가 제정한 기술기준과 시공기준을 업무에 적용하고 있는 실정이다. 아울러 방범설비협회를 중심으로 우량방범기기인정제도(RBSS: Recognition of Better Security System) 등을 시행하고 있다. 또 방범설비사와 종합방범설비사 자격제도를 도입하여 방범기기 설치 및 제조자의 능력을 향상시키고 생산기술 향상을 도모하고 있다. 그러나 우리나라의 경우는 경비업법에 따라 한국경비협회가 중심을 이루고 있지만, 경비시장의 중추를 이루고 있는 기계경비업체는 참여가 거의 없는 실정이다. 그렇다고 기계경비업체나 방범기기 제조업체와 설비업체들이 함께 할 수 있는 조직이 있는 것도 아니기 때문에 방범기기에 대한 통합된 노력을 할 수 없는 환경이다. 따라서 본 연구의 목적은 일본의 시큐리티산업과 방범설비산업의 현황 및 방범설비협회의 사업과 운영 등을 살펴보고 한국에 적용할 수 있는 시사점을 제시하는 것이다.

• 한국산학기술학회논문지
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• 제17권6호
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• pp.166-172
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• 2016

원자력발전소 일차 냉각계통 주요 설비의 외부면에 열차폐를 위해 설치되는 반사형 금속단열재의 내진 성능을 확인하기 위한 연구가 수행되었다. 추후 실제 내진 시험 수행을 대비하기 위해서 국내 내진시험 시설에서 시험이 가능한 시편의 크기와 무게의 한도를 고려하여 원전 원자로압력용기의 실제 동특성과 근접한 진동 특성을 가지는 축소모델을 설계하였다. 또한 축소모델의 외곽에 금속단열재를 설치한 유한요소해석 모델을 작성하였으며, 등가정적해석법 및 응답스펙트럼해석법을 통해서 국내 원전의 안전정지지진 층 응답스펙트럼을 적용하여 내진해석을 수행하였다. 보수성을 확보하기 위하여 일차 냉각계통 주요 기기들의 층 응답스펙트럼들을 포괄하는 포괄 응답스펙트럼을 작성하여 가진 데이터로서 사용하였다. 해석 결과 최대응력이 금속단열재 재질의 항복응력보다 충분히 작게 나오는 것을 확인하였고, 따라서 국산화 개발 중인 반사형 금속단열재가 안전정지지진이 발생할 경우에도 구조적 건전성을 유지할 수 있음을 해석을 통해 확인하였다. 본 연구 결과는 추후 수행할 예정으로 있는 내진시험 결과와 비교할 예정이며 이를 통하여 국산화된 금속단열재의 내진 성능을 확보할 수 있고 내진해석과 내진시험을 비교 분석하여 내진검증방법을 체계적으로 구축할 수 있을 것이다.

• 한국안전학회지
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• 제35권2호
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• pp.8-16
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• 2020

In Article 311 of the Regulation on Occupational Safety and Health Standards requires the use of Korean Industrial Standards Act in accordance with the Industrial Standardization Act. However, the classification, inspection, maintenance, design, selection, and installation of explosion hazard locations for explosion and explosion prevention and internalization of 'safety' in the performance maintenance phase of electrical machinery and equipment There is no technical and institutional management plan for remodeling and alteration. Analysis of actual conditions and problems related to the installation, use, and maintenance of explosion-proof equipment, comparative analysis of domestic and international technical standards and systems, technical, institutional and administrative systems and systems related to installation, use, and maintenance of explosion-proof equipment, technical personnel and qualifications, etc. It is to propose legislation, system improvement, and technical standard establishment related to the maintenance of explosion-proof facility performance through improvement of the necessity and feasibility study for establishment of the legal status of the management site and management plan. As technical measures, KS standard revision (draft), KOSHA guide (draft) and explosion-proof facility performance maintenance manual were presented. In addition, the institutional management plan proposed the revised rule on occupational safety and health standards, the revised rule on the restriction of employment of hazardous work, and the manpower training program related to the maintenance of explosion-proof facilities and the qualification plan. Enhance safety at the installation, use, and maintenance stage of explosion-proof structured electrical machinery. It is expected to be used to classify explosion hazards, select related equipment, and to update and standardize standards related to installation, use and maintenance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.755-762
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• 2004

In our country, when the replacement for individual components of equipment in nuclear power plants is required, establishment of individual criteria i.e. Required Response Spectra(RRS) of seismic test/analysis for the component is very difficult because of the absence of Test Response Spectra(TRS) for the individual component to be replaced, from the existing qualification documents. In this case, it is required to perform the structural analysis for the nuclear equipment including the components to be replaced. After the structural analysis, Analysis Response Spectra(ARS) at the point of the component shall be generated and used for seismic test of the component. However, as of today, no standard program authorized for the response spectra generation by using the structural analysis exists in korea. Because of above reason, the STAR-Egs computer program was developed by using the method which calculates directly the expected response spectrum(frequency vs. acceleration type) of the selected points in the nuclear equipment with input spectrum(Required Response Spectra, RRS), based on the dynamic characteristics of the Finite Element(FE) model that is equivalent to the nuclear equipment. The STAR-Egs controls ANSYS/I-DEAS commercial software and automatically extract modal parameters of the FE model. The STAR-Egs calculates response spectrum using the established algorithm based on the extracted modal parameters, too. Reliance on the calculation result of the STAR-Egs was verified through comparison output with the result of MATLAB commercial software based on the identical algorithm. Moreover, actual seismic testing was performed as per IEEE344-1987 for the purpose of program verification by comparison of the FE analysis results.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1382-1393
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• 2022

This paper investigates the seismic behavior of an electrical cabinet considering the influence of equipment-anchor-interaction (EAI) that is generally not taken into consideration in a decoupled analysis. The hysteresis behavior of an anchor bolt in concrete was thereby considered to highlight this interaction effect. To this end, the experimental behavior of an anchor bolt under reversed cyclic loading was taken from the recently developed literature, and a numerical model for the anchor hysteresis was developed using the component approach. The hysteresis properties were then used to calibrate the multi-linear link element that is implemented as a boundary condition for the cabinet incorporating the EAI. To highlight this EAI further, the nonlinear time history analysis was performed for a cabinet considering the hysteresis behavior comparative to a fixed boundary condition. Additionally, the influence on the seismic fragility was evaluated for the operational and structural condition of the cabinet. The numerical analysis considering the anchor hysteresis manifests that the in-cabinet response spectra (ICRS) are significantly amplified with the corresponding reduction in the seismic capacity of 25% and 15% for an operational and structural safety condition under the selected protocols. Considering the fixed boundary condition over a realistic hysteresis behavior of the anchor bolt is more likely to overestimate the seismic capacity of the cabinet in a seismic qualification procedure.

• 한국전산유체공학회지
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• 제21권4호
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• pp.78-84
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• 2016

In this paper, turbulence models for considering roughness in the open source code(OpenFOAM) was investigated. Wall function in the RANS(Reynolds-averaged Navier - Stokes) turbulence model was modified considering roughness on the flat plate by using roughness function. Correlation between the first layer height in the CFD model and roughness height of the plate was observed, and the most proper roughness function, and the first layer height from the plate wall in the CFD analysis was suggested in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1911-1912
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• 2006

원자력 발전소가 전력계통으로부터 분리되어 외부전원으로 발전소 내부의 주요 보조기기들을 운전할 수 없는 상황에서 비상디젤 발전기는 원자력발전소의 핵심 냉각펌프 등 전원을 공급하지 않으면 안 된다. 현재까지는 품질등급 Q-Class인 비상 발전기 여자시스템이 외국 기술에 전적으로 의존하여 공급되었는데 비상발전기가 차지하는 역할의 중요성으로 인한 품질활동 절차, 규제기관의 인허가 획득 등의 문제 때문에 비상 디젤발전기의 여자시스템이 현재까지 국산 연구개발이 이루어지지 않았다. 본 논문은 원전 비상디젤 발전기 여자시스템의 국산개발에 필요한 시스템의 기기 검증에 대한 내용을 기술하고자 한다.