An important goal of dismantling process is the disassembling of a spent nuclear fuel assembly for the subsequent extraction process. In order to design the rod extractor and cutter, the major requirements were considered, and the modularization design was carried out considering remote operation and maintenance. In order to design the rod extractor and cutter, these systems were analyzed and designed, also the concept on the rod extraction and cutting were considered by using the solid works tool. The main module consists of five sub-modules, and the function of each is as follows. The clamping module is an assembly fixing module using a cylinder so that the nuclear fuel assembly can be fixed after being placed. The Pusher module pushes the fuel rods by 2 inches out of the assembly to grip the fuel rods. The extraction module extracts the fuel rods of the nuclear fuel assembly and moves them to the consolidation module. The consolidation module collects and consolidates the extracted fuel rods before moving them to the cutting device. And the support module is a base platform on which the modules of the main device can be placed. The modules of level 2 can be disassembled or assembled freely without mutual interference. For the design of fuel rods cutter, the following main requirements were considered. The fuel rod cut section should not be deformed for subsequent processing, and the horizontally mounted fuel rods must be cut at regular intervals. The cutter should have the provision for aligning with the fuel rod, and the feeder and transport clamp should be designed to transfer the fuel rods to the cutting area. The main module consists of 6 sub-modules, and function of each is as follows. The cutting module is a device that cuts the fuel rods to the appropriate depth for notching. The impacting module is a device that impacts the fuel rods and moves them to the collection module. The transfer module is a device that moves the fuel rods to the cutting module when the aligned fuel rods enter the clamp module. The clamping module is a device to clamp the fuel rods before moving them to the cutting module. The collection module is a container where the rod-cuts are collected, and the support module is a base platform on which the modules of the main device can be placed. The module of level 3 can be disassembled or assembled after the cutting module of level 2 is installed, and the modules of level 2 can be disassembled or assembled freely without mutual interference.

In the wake of the Fukushima NPP accident, research on the safety evaluation of spent fuel storage facilities for natural disasters such as earthquakes and tsunamis has been continuously conducted, but research on the protection integrity of spent fuel storage facilities is insufficient in terms of physical protection. In this study, accident scenarios that may occur structurally and thermally for spent fuel storage facilities were investigated and safety assessment cases for such scenarios were analyzed. Major domestic and international institutions and research institutes such as IAEA, NEA, and NRC provide 13 accident scenario types for Spent Fuel Pool, including loss-of-coolant accidents, aircraft collisions, fires, earthquakes. And 10 accident scenario types for Dry Storage Cask System, including transportation cask drop accidents, aircraft collisions, earthquakes. In the case of Spent Fuel Pool, the impact of the cooling function loss accident scenario was mainly evaluated through empirical experiments, and simulations were performed on the dropping of spent nuclear fuel assembly using simulation codes such as ABAQUS. For Dry Storage Cask System, accident scenarios involving structural behavior, such as degradation and fracture, and experimental and structural accident analyses were performed for storage cask drop and aircraft collision accidents. To evaluate the safety of storage container drop accidents, an empirical test on the container was conducted and the simulation was conducted using the limited element analysis software. Among the accident scenarios for spent fuel storage facilities, aircraft and missile collisions, fires, and explosions are representative accidents that can be caused by malicious external threats. In terms of physical protection, it is necessary to analyze various accident scenarios that may occur due to malicious external threats. Additionally, through the analysis of design basis threats and the protection level of nuclear facilities, it is necessary to derive the probability of aircraft and missile collision and the threat success probability of fire and explosion, and to perform protection integrity evaluation studies, such as for the walls and structures, for spent fuel storage facilities considering safety evaluation methods when a terrorist attack occurs with the derived probability.

대다수의 부유식 해양플랜트는 위치 유지의 방법으로서 체인 계류 시스템을 사용하나, 그 설계 변경 과정은 논문으로 찾아보 기 힘들다. 본 연구는 FLBT를 대상 해양플랜트로 선정하여 계류 초기설계안과 모형시험을 수치해석으로 분석하고, 변경된 설계조건에 따 라 새로운 계류 설계안을 제시하였다. 주된 환경 방향에 따라 계류선 묶음(bundle)의 주 방향을 조절하는 것이 계류 설계하중 감소에 크게 유효했다. 터렛 계류된 해양플랜트라도 횡파에 노출되며, 횡파 중 운동 때문에 높은 계류 인장력이 발생했다. 일치된 환경 방향 조건은 설 계조건이 될 수 없으며, 바람, 파도, 조류의 각 환경 방향이 복잡한 조건에서 설계 계류 하중이 발생했다. 횡요 운동이 계류 인장력에 미치 는 영향이 큼으로 적절한 횡요 감쇠 계수를 계류해석에 적용하는 것이 중요하다.

이 논문에서는 기존의 조인트 교량을 일체식 교대 교량으로 변경할 경우, 온도하중에 의한 상부구조의 인장에 따른 흉벽의 휨거동을 보강하기 위한 흉벽 FRP 보강공법을 제안하고, 설계 및 유한요소해석을 통해 보강 효과를 검토하였다. FRP 보 강재는 펄트루젼 공정으로 제작하며, 흉벽 전면부에 부착하여 일체식 교대 교량으로 변경할 때, 흉벽에 부족한 인장철근의 역할 을 대체하게 된다. 흉벽 FRP 보강공법의 설계는 ACI Committee 440을 참고하여 수행하였으며, 유한요소해석은 콘크리트, 철근 및 유리섬유와 비닐에스터로 제작한 FRP 보강재의 최대응력을 보강 방법에 따라 비교하였다. 유한요소해석 결과, FRP 보강재는 콘크리트에 발생하는 인장응력을 감소시키는 역할을 하며, 흉벽이 저항할 수 있는 휨모멘트를 증가시킬 수 있는 것으로 나타났 다.

국내 현대정원의 조성 디자인 경향성을 확인하고자 우수 경 관 정원 80개소 대상으로 적용 양식 및 정원 식물을 조사하였 다. 조사 대상 80개소 정원 중 53.7%는 서울 및 수도권, 46.3%는 그 외 지역에 소재하고 있다. 또한, 관리 유형에 따 라 공동 정원, 상업시설 정원, 개인 정원으로 구분 되었으며, 각 62.5%, 21.3%, 16.2%로 나타났다. 19~20세기 해외 정원 사조에 따라 조성 양식은 12유형(정형식, 비정형식, 정형 및 비정형 복합식, 건축식, 자연, 신풍경, 뉴저먼 스타일, 모더니 즘, 프레리 스타일, 뉴웨이브 스타일, 낭만주의, 예술작품 정 원)으로 분류되었다. 우리나라 현대 정원은 단일 및 복합 양식 활용이 각 55.0%와 45.0%로 유사하였다. 주로 정형 및 비정 형 복합식 정원이 활용되는 반면, 정형 및 비정형 복합식 정원 대비 낭만주의, 모더니즘, 프레리 및 뉴웨이브 스타일 이용 빈 도는 0.02~0.06배 수준이었다. 조성 양식 활용에 따라 이용 되는 식물 소재 유형에는 큰 차이가 없었으나, 특정 디자인에 서 식재 빈도가 높은 분류군을 확인했다.

게임의 세계는 최근 몇 년간 빠르게 진화해 왔다. 특히 여성 게이머들의 수가 증가하면서, 이들의 구체적인 요구를 이해할 필요성이 대두되고 있다. 본 연구는 여성 데이트 시뮬레이션 모바일 게임 및 게임 캐릭터 디자 인 분야에서 여성 게임 이용자의 요구와 선호를 분석하고자 한다. 최근에는 여성 중심의 게임에 대한 관심이 증가하고 있지만, 여성 게임 플레이어를 대상으로 한 게임은 아직 충분히 개발되지 않았다. 따라서 본 연구에 서는 광범위한 문헌 검토와 설문조사를 통해 여성 게이머들의 선호를 파악하고, 이를 바탕으로 여성 데이트 시뮬레이션 모바일 게임의 캐릭터 디자인 방향을 제안한다. 이를 통해 게임 디자이너 및 개발자들은 현대 여 성들의 요구를 더욱 잘 이해하고, 높은 수준의 게임을 개발할 수 있을 것이다. 더 줄일 수 있다. 그리고 제안 된 모델은 앞으로 다른 게임이나 스포츠 게임에도 적용될 것이다.

The automatic dust separator is a device installed in the suction tank of the pumping or drainage plant, and prevents foreign substances such as aquatic plants or wood chips from being sucked into the underwater pump. Since the dust separator obstructs the flow of water for separating dusts, a water level difference is likely to occur before and after the dust separator. Since the water level difference before and after the dust separator acts as an additional hydraulic load on the dust separator structure, it may reduce the lifetime of the dust separator and cause damage. In this study, in order to reduce the water level difference, we devised changing the existing I-beam-shaped dust separator parts to a streamlined shape, and quantitatively analyzed the water level difference before and after the dust separator, hydraulic load, and flow velocity distribution through computational fluid analysis to confirm the effect of design improvement.

The external weather conditions including temperature and wind speed in the Saemangeum reclaimed land is different from that of the inland, affecting the internal environment of the greenhouse. Therefore, it is important to select an appropriate covering material considering the insulation effect according to the type and characteristics of the covering material considering the weather condition in the Saemangeum reclaimed land. A hexahedral insulation chamber was designed to evaluate the insulation efficiency of each glass-clad material in the outside weather condition in reclaimed land. In order to evaluate the insulation effect of each covering material, a radiator was installed and real-time power consumption was monitored. 16-mm PC (polycarbonate), 16-mm PMMA (polymethyl methacrylate), 4-mm greenhouse glass, and 16-mm double-layered glass were used as the covering materials of the chamber. In order to understand the effect of the external wind directions, the windward and downwind insulation properties were evaluated. As a result of comparing the thermal insulation effect of each greenhouse cover material to single-layer glass, the thermal insulation effect of double-layer glass was 16.9% higher, while PMMA and PC were 62.5% and 131.2% higher respectively. On average the wind speed on the windward side was 53.1% higher than that on the lee-wind side, and the temperature difference between the inside and outside of the chamber at the wind ward side was found to be 52.0% larger than that on the lee ward side. During the experiment period, the overall heating operation time for PC was 39.2% lower compared to other insulation materials. Showing highest energy efficiency, and compared to PC, single-layer glass power consumption was 37.4% higher.

본 논문에서는 역전파 방법 기반 자동미분법을 이용하여 설계민감도를 구하고 이를 응력제한조건을 고려한 위상최적설계에 적용 하였다. 응력제한조건이 있는 위상최적화문제는 특이점(singularity)과 응력의 국부성(local nature of stress constraint)문제, 그리고 설 계 변수에 대한 비선형성의 문제를 포함하고 최적해를 얻기가 매우 힘들다. 특이점 문제를 해결하기 위해서 응력 완화(stress relaxation) 기법을 사용하였고, 응력의 국부성을 해결하기 위해 p-norm을 이용한 전역 응력치를 제한조건에 사용하였다. 설계 변수에 대한 비선 형성을 극복하기 위해 해석적인 방법으로 정확한 설계민감도를 구하는 것이 중요하다. 위상최적설계에서 기존에는 보조변수방법 (adjoint variable method)을 사용하여 빠르고 정확한 설계민감도를 구했지만, 설계민감도를 해석적으로 구해야 하고, 보조평형방정식 을 추가로 풀어야 하는 어려움이 있다. 이를 해결하기 위해서 인공신경망에서 최적 가중치(weights)와 편차(biases)를 구할 때 쓰이는 역전파 기법을 이용하여 설계민감도를 구하고 이를 응력제한조건을 고려한 위상최적설계에 적용하였다. 역전파 기법은 자동미분에 쓰이는 기법으로 목적함수나 제한조건에 대한 설계민감도를 별도의 수식유도 없이 간단하게 구할 수 있는 장점이 있다. 또한, 미분값 을 구하는 역전파의 과정이 보조평형방정식을 푸는 것보다 계산시간이 빠르고 해석적 방법으로 구한 설계민감도와 같은 정확도를 보 여준다

Complaints about foul odors are emerging as an issue, and the number of complaints is steadily increasing every year. Biofiltration is known to remove harmful or odorous substances from the atmosphere by using microorganisms, and full-scale biofilters are being installed and operated in various environmental and industrial facilities. In this study, the current status and actual odor removal efficiency of full-scale biofilters installed in publicly owned treatment facilities such as sewage, manure, and livestock manure treatment plants were investigated. In addition, the effects of design and operating factors on their efficiency were also examined. As a result, it was found that odor prevention facilities with less than 30% odor removal efficiency based on complex odors accounted for 40%-50% of the biofilters investigated. In investigating the appropriate level of operating factors on odor removal efficiency, it was found that compliance with the recommended values p lays a significant role in improving odor removal efficiency. In the canonical correlation analysis for the on-site biofilter operation and design data, residence time and humidity were found to be the most critical factors. The on-site biofilter operation and design data were analyzed through canonical correlation analysis, and the residence time and humidity maintenance were found to be the most important factors in the design and operations of the biofilter. Based on these results, it is necessary to improve the odor removal efficiency of on-site biofilters by reviewing the effectiveness of the operation factors, improving devices, and adjusting operating methods.

본 논문에서는 3차원 엮임 재료의 유체투과율 향상을 목적으로 수치해석 데이터 기반의 물성치 회귀 분석 및 최적설계를 소개한다. 우선 3차원 엮임 재료를 구성하는 와이어 사이의 간격을 결정하는 배율 계수를 매개변수화 하여 다양한 배율 조합을 가지는 수치 모 델을 생성하였고, 전산 수치해석을 통해 계산된 각 모델의 체적 탄성계수, 열전도 계수, 유체투과율 데이터를 이용하여 다항식 기반의 회귀 분석을 수행하였다. 이를 사용해서 체적 탄성계수와 유체투과율 사이의 다목적함수 최적설계를 통한 파레토 최적해를 도출하였 으며, 두 물성치가 서로 상충 관계에 있음을 확인하였다. 한편 3차원 엮임 재료의 열전달 효율을 높이기 위해서 유체투과율을 최대화 시키는 것을 목적으로 경사도 기반 최적설계를 수행하였고, 제약조건인 체적 탄성계수의 크기별 유체투과율의 변화율을 분석하였다. 그 결과 설계자가 원하는 최소한의 강성을 가지는 최대 유체투과율 설계 모델을 얻어낼 수 있음을 확인하였으며, 회귀 방정식을 통해 서 얻어진 설계가 높은 정확도를 가지고 있음을 추가적으로 검증하였다.

This study analyzes the effects of the number of angles and bends on resistance in a conductor-embroidered stitch circuit for efficient power transfer through a conductor of wearable energy harvesting to study changes in power lost through connection with actual solar panels. In this study, the angle of the conductive stitch circuit was designed in units of 30°, from 30° to 180°, and the resistance was measured using an analog Discovery 2 device. The measured resistance value was analyzed, and in the section of the angle where the resistance value rapidly changes, it was measured again and analyzed in units of 5°. Following this, from the results of the analysis, the angle at which the tension was applied to the stitch converges was analyzed, and the resistance was measured again by varying the number of bends of the stitch at the given angle. The resistance decreases as the angle of the stitch decreases and the number of bends increases, and the conductor embroidery stitch can reduce the loss of power by 1.61 times relative to general embroidery. These results suggest that the stitching of embroidery has a significant effect on the power transfer in the transmission through the conductors of wearable energy harvesting. These results indicate the need for a follow-up study to develop a conductor circuit design technology that compares and analyzes various types of stitches, such as curved stitches, and the number of conductors, so that wearable energy harvesting can be more efficiently produced and stored.

The flange spreader has been used to withdraw gaskets and valves during butterfly valve maintenance. When using the conventional flange spreader, an excessive working space (pipe separation distance) appears, and the pipe and flange are damaged by the load. Also, the equipment can’t be operated safely when the pipe has eccentric fitting. To solve the problems, a valve easy out tool with collet was developed for safely fixing and spreading flange. By using Ansys Workbench 2021 R2, the structural analysis of the original collet was performed, and shape design of the collet was carried out to improve structural safety.

Dry head end process is developing for pyro-processing at KAERI (Korea Atomic Energy Research Institute). Dry processes, which include disassembling, mechanical decladding, vol-oxidation, blending, compaction, and sintering shall be performed in advance as the head-end process of pyro-processing. Also, for the operation of the head-end process, the design of the connecting systems between the down ender and the dismantling process is required. The disassembling process includes apparatus for down ender, dismantling of the SF (Spent Fuel) assembly (16×16 PWR), rod extraction, and cutting of extracted spent fuel rods. The disassembling process has four-unit apparatus, which comprises of a down ender that brings the assembly from a vertical position to a horizontal position, a dismantler to remove the upper and bottom nozzles of the spent fuel assembly, an extractor to extract the spent fuel rods from the assembly, and a cutter to cut the extracted spent fuel rods as a final step to transfer the rod-cuts to the mechanical decladding process. An important goal of dismantling process is the disassembling of a spent nuclear fuel assembly for the subsequent extraction process. In order to design the down ender and dismantler, these systems were analyzed and designed, also concept on the interference tools between down ender and dismantler were considered by using the solid works tool.

The bilateral nuclear cooperation agreement provides the basis for technical and economic exchanges and research and development cooperation in the nuclear industry, while also having an important role in the peaceful use of nuclear power. The government of Republic of Korea has signed the supplementary and additional arrangements with the United States, Canada, and Australia to specify detailed procedures necessary for the implementation of the agreement. Currently, items under the bilateral nuclear cooperation agreement (i.e., obligated items) are managed through official documents and e-mails, and it is difficult for the government to systemically track item inventory and identify the person in charge. Another issue is the discrepancy of information between the annual report on obligated items and the report under the import and export procedure. In order to solve these problems, the government is establishing an import and export management system for obligated items to enhance transparency and national reliability in Korea. The ultimate purpose of this project is to not only faithfully fulfill the obligations under the bilateral nuclear cooperation agreement, but also to increase the efficiency of implementation work through systematization of databases and management of obligated items. In this paper, an improved management procedures are suggested by analyzing the required functions and problems. Also, this paper provides a conceptual design that can be applied to the management system for it obligated items by identifying and analyzing practical problems in the import and export management of mandatory items. As a result, key considerations and the conceptual design proposal for the ‘export and import management system for items subject to the nuclear bilateral cooperation agreement’ are derived. The result will be supplemented through continuous discussions with facility operators and the government to be utilized for detailed system design.

The purpose of the present research is to verify the design characteristics of the SMART facility for the application of the IAEA’s safeguards-by-design (SBD) concept to small modular reactor (SMR) and to establish a foundation for SBD to be faithfully implemented as early as possible from the design stage. International Atomic Energy Agency (IAEA) is planning to facilitate the verification activities of inspectors by developing a safeguards approach to the reactor as early as possible and preparing a safeguards technical report (STR) before commercial operation of SMR begins. To this end, the IAEA is developing various approaches to the application of SBD to SMR with countries such as Republic of Korea, Russian Federation, China, the United States, and Canada through the Member State Support Program (MSSP). In order to review the unique design information of SMART facilities, the only deployable SMR in Korea, and to establish safeguards from the early design stages of SMART, it is necessary to carry out the task through cooperation with the Korea Atomic Energy Research Institute (KAERI) and Korea Institute of Nuclear Nonproliferation and Control (KINAC). IAEA agreed with the KINAC and KAERI to the direction of the project and to prepare both the Design Information Questionnaire (DIQ) and the Safeguards Technical Report (STR) for SMART facilities sequentially. The DIQ is a collection of questions to understand the characteristics of the reactor facilities that must be considered in applying safeguards. The STR is a document referenced by IAEA inspectors when verifying safeguards. Those draft versions were prepared and submitted to the IAEA. After review opinions were received, additional revision was conducted. In 2022, the IAEA holds the consultancy meeting on SBD for SMART. The purpose of the meeting is to review the draft DIQ and STR prepared by designers and discuss the future work plan of the task with designer and the task point of contact in order to safeguards can be considered at the early stage of the design. The results will be beneficial to the efficient safeguards verification activities of IAEA inspectors in the future.

Recently, about 70 Small Modular Reactors (SMRs) are being developed around the world due to various advantages such as modularization, flexibility, and miniaturization. An innovative SMR (i- SMR) is being developed in South Korea as well, and the domestic nuclear utility is planning to apply for the Standard Design Approval in 2026 after completing the basic design and standard design. Accordingly, the regulatory body is conducting research on the regulatory system for reviewing the i- SMR standard designs by referring to the IAEA and the U.S. NRC cases. A SMR is expected to many changes not only in terms of cyber security due to new digital technology, remote monitoring, and automatic operation, but also in terms of physical security according to security systems, security areas, and vital equipment. Accordingly, related technical documents issued by the IAEA require nuclear utilities to consider regulatory requirements of security from the design phase by integrating security regulations into SMR licensing. The U.S. NRC has also identified 17 issues affecting SMR design since 2010 (SECY-10-0034), and among them, ‘Consideration of SMR security requirements’ was included as a major issue. Accordingly, the NuScale applicant conducted security assessment and design in consideration of the Design Base Threat (DBT) in the initial SMR design process through the Gap Analysis Report (2012) and the NuScale’s Security System Technical Report (TR-0416-48929), and the NRC developed the Design Specific Review Standard for NuScale (DSRS) and then reviewed the applicant’s security design process, standard design results, and testing criteria for security system (ITAAC). This paper analyzed the case of security review activities during the NuScale standard design review, and through this, it is intended to be used in the development of domestic regulatory system for the i-SMR security review in the future.

The sub-frame is located on the lower body of a monocoque type vehicle and serves as an engine and suspension, and is an important object part that receives a lot of load. The existing press-type sub-frame has a large number of parts for assembling, which causes an increase in cost. Changing the machining form of this part from the existing press-type machining method to the hydro-forming machining method has the advantage of reducing the cost and weight at the same time due to the reduction of the process. Therefore, in this study, the purpose of this study is to change the design so that the sub-frame of the existing press type can be changed to the hydro-forming process method. To this end, we intend to present a design method by analyzing the effect on the rigidity of the sub-frame using the existing machining method through shape optimization analysis.

Seismic demand on nonstructural components (NSCs) is highly dependent on the coupled behavior of a combined supporting structure- NSC system. Because of the inherent complexities of the problem, many of the affecting factors are inevitably neglected or simplified based on engineering judgments in current seismic design codes. However, a systematic analysis of the key affecting factors should establish reasonable seismic design provisions for NSCs. In this study, an idealized 2-DOF model simulating the coupled structure-NSC system was constructed to analyze the parameters that affect the response of NSCs comprehensively. The analyses were conducted to evaluate the effects of structure-NSC mass ratio, structure, and NSC nonlinearities on the peak component acceleration. Also, the appropriateness of component ductility factor (R p) given by current codes was discussed based on the required ductility capacity of NSCs. It was observed that the responses of NSCs on the coupled system were significantly affected by the mass ratio, resulting in lower accelerations than the floor spectrum-based response, which neglected the interaction effects. Also, the component amplification factor (a p) in current provisions tended to underestimate the dynamic amplification of NSCs with a mass ratio of less than 15%. The nonlinearity of NSCs decreased the component responses. In some cases, the code-specified R p caused nonlinear deformation far beyond the ductility capacity of NSCs, and a practically unacceptable level of ductility was required for short-period NSCs to achieve the assigned amount of response reduction.