• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3732-3744
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• 2022

To investigate the effects of ocean conditions on the thermal stress and deformation caused by thermal stratification of a pressurizer surge line in a floating nuclear power plant (FNPP), the finite element simulation platform ANSYS Workbench is utilized to conduct the fluid-solid-thermal coupling transient analysis of the surge line under normal "wave-out" condition (no motion) and under ocean conditions (rolling and pitching), generating the transient response characteristics of temperature distribution, thermal stress and thermal deformation inside the surge line. By comparing the calculated results for the three motion conditions, it is found that ocean conditions can significantly improve the thermal stratification phenomenon within the surge line, but may also result in periodic oscillations in the temperature, thermal stress, and thermal deformation of the surge line. Parts of the surge line that are more susceptible to thermal fatigue damage or failure are determined. According to calculation results, the improvements are recommended for pipeline structure to reduce the effects of thermal oscillation caused by ocean conditions. The analysis method used in this study is beneficial for designing and optimizing the pipeline structure of a floating nuclear power plant, as well as for increasing its safety.

• 시스템엔지니어링학술지
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• 제17권2호
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• pp.37-48
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• 2021

Improving the plant protection system against unforeseen changes/transients during operation is essential to maintain plant safety. Under this condition, it requires rapid and accurate signal processing. The use of an Intellectual Property (IP) core for floating point calculations for Safety Critical MMIS can make numerical computations easier and more precise, improving system accuracy. It can represent and manipulate rational numbers as well as a much broader range of values with dynamic range in nuclear power plant. Systems engineering approach (SE) is used through the development process, it helps to reduce complexity and avoid omissions and invalid assumptions as delivers a better understanding of the stakeholders needs. For the implementation on the FPGA target board, the 32-bit floating-point arithmetic with IEEE-754 standards has designed using Simulink model in Matlab for all operations of addition, subtraction, multiplication and division and VHDL code generated.

• Earthquakes and Structures
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• 제14권1호
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• pp.33-44
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• 2018

Base-isolated nuclear power plant (BI-NPP) structures are founded on expanded basemat as a flexible floating nuclear island, are still lacking the recommendation of the consideration of incoherent motion effect. The effect of incoherent earthquake motion on the seismic response of BI-NPP structure has been investigated herein. The incoherency of the ground motions is applied by using an isotropic frequency-dependent spatial correlation function to perform the conditional simulation of the reference design spectrum compatible ground motion in time domain. Time history analysis of two structural models with 486 and 5 equivalent lead plug rubber bearing (LRB) base-isolators have been done under uniform excitation and multiple point excitation. two different cases have been considered: 1) Incoherent motion generated for soft soil and 2) Incoherent motion generated for hard rock soil. The results show that the incoherent motions reduce acceleration and the lateral displacement responses and the reduction is noticeable at soft soil site and higher frequencies.

• 신재생에너지
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• 제9권4호
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• pp.25-31
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• 2013

This paper describes an electrical linear generator (IntELG) based on permanent magnets, containing heaving buoy, and its applications for the floating wave energy converters riding in parallel waves. The permanent magnets are integrated with the heaving buoy as a component and the integrated component is configured within the cylindrical IntELG to be filled with fluid. Thus, the IntELG can effectively be applied for the power-take-off of the floating wave energy converter riding in parallel waves. Typical applications are exampled with the Pelamis and Anaconda and they are investigated for the diversely redundant power source of nuclear power plant and the cooperation with submerged tunnel(s).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1233-1234
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• 2011

• 한국전자통신학회논문지
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• 제13권1호
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• pp.35-44
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• 2018

우리나라 정부는 화력과 원자력발전소를 줄이고 2030년까지 깨끗한 재생에너지 전기를 20% 생산하는 목표를 갖고 있다. 태양에너지는 기술적으로 전 세계 에너지수요를 초과하는 잠재자원이다. 비용절감을 가져오는 기술적인 진보 및 재생에너지 개발과 활용을 위한 정부정책에 힘입어 태양에너지산업은 최근 괄목할만한 성장을 가져오고 있다. 비록 태양광발전은 다른 전력생산 방식보다 많은 장점을 가지고 있음에도 불구하고 주요 문제는 이용할 수 있는 현장과 적절한 비용을 갖춘 부지가 많지 않다는 것이다. 본 연구에서는 전라남도 지역을 대상으로 설치 가능한 육상 및 수상태양광 용량을 분석하고자 한다. 연구결과 설계용량은 육상풍력 약 7.5GW와 수상태양광 약 1.5GW를 갖는다. 또한, 지역주민과 이해간격을 줄이기 위한 목적으로 설득에 필요한 여러 가지 해결방법을 제시하였다.

• 해양환경안전학회지
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• 제30권5호
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• pp.499-505
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• 2024

지구온난화 문제에 대응하기 위해 온실가스 배출 저감을 위한 다양한 규제와 정책이 시행되고 있다. 이러한 배경 속에서 탄소중립을 목표로 하는 국가들이 늘어나고 있으며, 이에 따라 소형원자로모듈(Small Modular Reactor 이하 SMR)이 새로운 발전소 모델로 주목받고 있다. SMR은 전통적인 대형 원자력 발전소 크기의 5~10% 수준이지만, 수백 메가와트(MW)급의 발전 용량을 갖춘 고효율시스템이다. 이 발전소는 화석 연료 기반 발전소에 비해 탄소 발생을 줄일 수 있으며, 신재생에너지의 불안정한 에너지 공급을 보완할 수 있는 장점이 있다. 하지만, 원자력 발전소는 사고 시 방사선물질 누출의 위험성이 있어 주변 주민의 반대를 받아 왔다. 이러한 문제를 해결하기 위해 부유식 소형 원자력 발전선이 주목받고 있다. 부유식 소형 원자력 발전소는 해양에 설치되어 부지확보, 인근 거주민 보상, 협의 과정이 간소화되고, 자연재해에 대한 안전성이 높다. 본 연구에서는 SMR 발전선의 파랑 중 예인 안정성을 평가 하였다. 해상상태 3, 4, 5에서의 운동해석 결과, 해상상태 5 이하에서는 예인하여 목적지까지 이동하는데 필요한 내항성능 기준을 만족시킬 수 있음을 확인하였다.

• Structural Engineering and Mechanics
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• 제76권3호
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• pp.367-378
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• 2020

This paper presents a new design concept for ocean nuclear power plants (ONPPs) using a tension leg platform (TLP). The system-integrated modular advanced reactor, which is one of the successful small modular reactors, is mounted for demonstration. The authors define the design requirements and parameters, modularize and rearrange the nuclear and other facilities, and propose a new total general arrangement. The most fundamental level of design results for the platform and tendon system are provided, and the construction procedure and safety features are discussed. The integrated passive safety system developed for the gravity based structure-type ONPP is also available in the TLP-type ONPP with minor modifications. The safety system fully utilizes the benefits of the ocean environment, and enhances the safety features of the proposed concept. For the verification of the design concept, hydrodynamic analyses are performed using the commercial software ANSYS AQWA with the Pierson-Moskowitz and JONSWAP wave spectra that represent various ocean environments and the results are discussed.

• 한국해안해양공학회지
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• 제10권3호
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• pp.120-124
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• 1998

본 연구는 인공항 속에 떠 있는 원자로를 토네이도로부터 보호하기 시작되었다. 연구결과에 의하면 토네이도가 유발할 수 있는 파고는 8.2 m이다. 본 연구에 있어 바람의 마찰 전단력에 의하여 발생하는 파는 작다고 가정하여 무시하였다.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1738-1748
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• 2019

Previous research has shown that the inclined condition has an impact on the natural circulation (natural circulation) mode operation of Floating Nuclear Power Plant (FNPP) mounted on the movable marine platform. Due to its compact structure, small volume, strong maneuverability, the Integral Pressurized Water Reactor (IPWR) is adopted as marine reactor in general. The OTSGs of IPWR are symmetrically arranged in the annular region between the reactor vessel and core support barrel in this paper. Therefore, many parallel natural circulation loops are built between the core and the OTSGs primary side when the main pump is stopped. and the inclined condition would lead to discrepancies of the natural circulation drive head among the OTSGs in different locations. In addition, the flow rate and temperature nonuniform distribution of the core caused by inclined condition are coupled with the thermal hydraulics parameters maldistribution caused by OTSG group operating mode on low power operation. By means of the RELAP5 codes were modified by adding module calculating the effect of inclined, heaving and rolling condition, the simulation model of IPWR in inclined condition was built. Using the models developed, the influences on natural circulation operation by inclined angle and OTSG position, the transitions between forced circulation (forced circulation) and natural circulation and the effect on natural circulation operation by different OTSG grouping situations in inclined condition were analyzed. It was observed that a larger inclined angle results the temperature of the core outlet is too high and the OTSG superheat steam is insufficient in natural circulation mode operation. In general, the inclined angle is smaller unless the hull is destroyed seriously or the platform overturn in the ocean. In consequence, the results indicated that the IPWR in the movable marine platform in natural circulation mode operation is safety. Selecting an appropriate average temperature setting value or operating the uplifted OTSG group individually is able to reduce the influence on natural circulation flow of IPWR by inclined condition.