Bentonite, a material mainly used in buffer and backfill of the engineering barrier system (EBS) that makes up the deep geological repository, is a porous material, thus porewater could be contained in it. The porewater components will be changed through ‘water exchange’ with groundwater as time passes after emplacement of subsystems containing bentonite in the repository. ‘Water exchange’ is a phenomenon in which porewater and groundwater components are exchanged in the process of groundwater inflow into bentonite, which affects swelling property and radionuclide sorption of bentonite. Therefore, it is necessary to assess conformity with the performance target and safety function for bentonite. Accordingly, we reviewed how to handle the ‘water exchange’ phenomenon in the performance assessment conducted as part of the operating license application for the deep geological repository in Finland, and suggested studies and/or data required for the performance assessment of the domestic disposal facility on the basis of the results. In the previous assessment in Finland, after dividing the disposal site into a number of areas, reference and bounding groundwaters were defined considering various parameters by depth and climate change (i.e. phase). Subsequently, after defining reference and bounding porewaters in consideration of water exchange with porewater for each groundwater type, the swelling and radionuclides sorption of bentonite were assessed through analyzing components of the reference porewater. From the Finnish case, it is confirmed that the following are important from the perspective of water exchange: (a) definition of reference porewater, and (b) variations in cation concentration and cation exchange capacity (CEC) in porewater. For applying items above to the domestic disposal facility, the site-specific parameters should be reflected for the following: structure of the bedrock, groundwater composition, and initial components of bentonite selected. In addition, studies on the following should be required for identifying properties of the domestic disposal site: (1) variations in groundwater composition by subsurface depth, (2) variations in groundwater properties by time frame, and (3) investigation on the bedrock structure, and (4) survey on initial composition of porewater in selected bentonite The results of this study are presumed to be directly applied to the design and performance assessment for buffer and backfill materials, which are important components that make up the domestic disposal facility, given the site-specific data.

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.

Sensory evaluation of shucking pressure, pressure holding time, seeding method, difference in full shucking rate in the aquaculture area and shucking oyster was performed using an ultra-high pressure oyster shucking machine. The reaching time for each target pressure is 2.2-2.4 MPa/sec in the range of 180 MPa to 240 MPa. had a rate of pressure rise. There was a difference of 0.5-1.7℃ in the range of 24-27℃ in the seawater temperature before and after the pressure treatment inside the pressure vessel, but there was no specific increase or decrease in seawater temperature. When only the shucking pressure is increased without the pressure holding time, the critical shucking pressure at which the oyster shell is opened and the flesh is peeled in the range of 200 to 220 MPa. When the critical shucking pressure is reached, the oyster sample in the closed vessel is expected to be shucked by about 40%. If there is no pressure holding time when judged only by full shucking, an increase in pressure of about 1.5 MPa is required to further shuck 3% of the oyster population. The oyster samples cultivated in the south coast of Korea were subject to full shucking under the conditions of 220 MPa shucking pressure and two minutes (120 seconds) of pressure holding time, and the difference in the pressure of the oysters according to the oyster seeding method and the farming area was minute. Finally, the condition of 220 MPa of shucking pressure and three minutes of pressure holding time was the best at 1.52 when the result of the sensory evaluation performed manually was set to 1.0. Next was 1.4 under the conditions of 220 MPa of shucking pressure and one minute of pressure holding time (60 seconds), and 1.3 under the condition of 220 MPa and two minutes of pressure holding time (120 seconds). Therefore, it is considered that the most desirable shucking conditions, considering the efficiency and sensory evaluation results, are the conditions of 220 MPa shucking pressure and two to three minutes of pressure holding time.

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.

Since the National Research and Development Innovation Act. was enacted, evaluation and management of research outputs become more important. The research output is defined as all types of information resources produced from the scientific research activities in each research phase, such as learning, proposing, performing, and publishing. Among them, research outputs mainly from the publishing phase have been systematically managed, including articles, books, technical reports, patents, and software. KINAC, like other Korean R&D institutions, has also achieved growth in research outputs, through continuously increased investment in R&D projects. However, R&D productivity, technology transfer, and commercialization remain low level. The importance of R&D performance diffusion has been emphasized. It’s because the creation of economic value through the utilization of research results has been emerging as a key issue in R&D policy. Therefore, various policies are being nationally pursued to promote the utilization of research achievements, but the results are not being effectively utilized and disseminated. In the field of nuclear nonproliferation and security, it is also difficult to diffuse the R&D performance. In this study, the research outputs of KINAC from 2010 to 2021 were analyzed. A number of research outputs have been made and managed, but the R&D performances have not been analyzed and identified yet. In addition, supportive methods were suggested for efficient performance management toward diffusion. For this purpose, some policies of Korea and other countries concerning performance diffusion -related policies were reviewed. The best practices of performance management and applications were also reviewed and compared to the KINAC cases. As a result, the number of research output has dramatically increased during the last 10 years, showing an average annual total output of 84 and year-on-year increase of 18%. The biggest change was in the conference papers and journals, whereas, there were no trends by year in the case of the technical reports and patents. Of course, it was proportional to the size of the organization, the number of research projects, and its budget. Because many studies highlight the importance of institutional resources, capabilities, and processes for performance management as factors affecting efficient diffusion, the current status of our process was also identified. This study is expected to be applied to the improvement of the performance management of the institute, leading to the enhancement of the R&D performance application.

Failure to comply with the performance test requirements for the centrifugal pumps at power plants often results in performance dissatisfaction as a result of field tests. This study proposed a method of reducing the uncertainty of the field test results by evaluating the systematic error in the measurement system caused by failure to follow the test requirements using the computational fluid dynamics(CFD) technique. As a result of the evaluation of the systematic error and reflecting it in the performance test data, it was confirmed that the error occurred at a constant rate with respect to the flowrate and that the pump, which showed a difference in performance actually had the same performance.

As the demand for appropriate heat dissipation measures to improve product stability and performance continues to increase and product design becomes highly integrated, research to improve heat transfer performance while maintaining the same area or size is required. In this study, the sample-shaped aluminum plate was treated as upper-coating, and the thickness of the coating was divided into 1mm, 2mm, and 3mm, respectively, and the coating material was applied with silver, copper, and graphene. The temperature condition of the heat source was set to 473K, and heat dissipation analysis was performed under natural convection. The thermal performance was compared and analyzed through temperature distribution, flow velocity distribution, and heat flux, and it was confirmed that the high thermal conductivity of graphene compared to other materials had a dominant effect on the increase in the conduction heat transfer rate. And it was confirmed that the high surface temperature of the graphene coating also increased the heat transfer rate by convection, thereby enhancing the heat dissipation effect.

The smart factory is an important system that can reduce defects, maximize productivity, and respond to customer needs, from the labor-intensive era of traditional small and medium-sized manufacturing companies through the automation era to CPS using ICT. However, small and medium-sized manufacturers often fall short of the basic stage due to economic and environmental constraints, and there are many companies that do not even recognize the concept of a smart factory. In this situation, to expand the smart factory of small and medium-sized enterprises, the project to support the establishment of a smart factory for the win-win between large and small enterprises. The win-win smart factory construction support project provides a customized differentiation program support project according to the size and level of the company for all domestic manufacturing SMEs regardless of whether or not they are dealing with Samsung. In this study, we analyze the construction status and introduction performance of companies participating in the win-win smart factory support project to find out whether they have been helpful in management and to find efficient ways to improve support policies, and to suggest the direction of continuous support projects to improve the manufacturing competitiveness of SMEs in the future.

Radioactive waste disposal facility in Korea, radioactive waste packaged in 200 L drums is placed in a concrete disposal container and disposed of at an underground silo type (cave) disposal facility. At this time, the disposal container cover is seated on the top of the disposal container, and if the disposal container and the cover are not completely combined, the container cover is raised up from the top of the disposal container, so safety problems may occur when stacking the disposal container. Therefore, various methods exist to secure a margin for the pure height inside the disposal container. The disposal container cover only covers the upper surface of the container to shield radiation, and structural performance is not required. Therefore, the method of processing the cover, such as a method of making the cover of the disposal container thin, is the easiest method to apply. In this study, a method to reduce the thickness of the cover of a concrete disposal container was devised, and structural performance under usability conditions such as lifting and seating was analyzed. In addition, the disposal container cover has a reinforced concrete form in which dissimilar materials (concrete and steel) are combined, an integrated analysis was performed to secure the reliability of the analysis results for this, and the analysis results were described. It was found that the proposed disposal container cover structure can improve usability by reducing the stress concentration phenomenon.

본 연구는 장병의 적극적인 스트레스 대처를 위해서 군부대에 치유정원을 조성하는데 필요한 기초자료를 얻기 위한 것이다. 연구대상은 병사 296명과 간부 342명 등 총 638명이며, 설문조사는 2022년 2월 21일부터 25일까지 실시하였다. 병사들의 경우, 대부분은 여가를 생활관 주변, 운동시설과 주변, 충성마트와 주변에서 보내며, 옥외공간에서의 주요 이용행태는 휴대폰 사용, 운동, 휴식 등이었다. 평일 옥외공간에서의 여가는 30분 이내가 대부분이며, 주말에는 평일에 비하여 늘어나는 양상을 보였다. 옥외공간 이용 시 동반자 수는 평일과 주말 모두 2~3명이나 혼자서 이용하는 비율이 대부분이었다. 간부의 경우, 평일 주 이용 옥외공간은 산책로와 주변, 생활관 주변이었고 이용행태는 산책, 운동의 비율이 높아 병사와 큰 차이를 보였으며, 평일 옥외공간 체류 시간은 병사들은 10분 정도가 가장 높았으나 간부들은 30분 정도가 상대적으로 높았다. 옥외공간 이용 시 동반자 수는 간부들은 2~3명, 병사들은 혼자서 이용하는 비율이 상대적으로 높았다. 스트레스 해소를 위한 치유정원을 조성할 경우 기능공간에 대한 중요도는 병사집단의 경우 프라이버시 공간이 가장 높았고 자연감상 공간이 낮았으나 간부집단은 통합기능 공간, 산책 공간, 자연감상 공간이 상대적으로 높았다. 성취도는 병사집단의 경우 대화/소통 공간이 가장 높았고 자연감상 공간이 가장 낮았으며, 간부집단의 경우 산책 공간이 상대적으로 높고 프라이버시 공간이 가장 낮았다. 중요도-성취도 분석결과, 지속유지 영역에는 간부집단의 산책 공간, 대화/소통 공간 및 통합기능 공간이 포함되었고 집중지향영역에는 병사집단의 프라이버시 공간과 간부집단의 자연감상 공간, 프라이버시 공간이 포함되었다. 낮은 우선순위 영역은 병사집단의 자연감상 공간, 통합기능 공간, 산책 공간 등이, 과잉영역은 병사집단의 대화/소통 공간만이 포함되었다.

인류 문명은 재료의 발달과 함께 진화를 해왔으며 20세기 후반부터 등장한 스마트재료는 외부 환경에 맞춰 스스로 적응을 하는 재료이다. 많은 종류의 스마트재료 중 대표물질이라고 할 수 있는 형상기억합금은 온도에 반응하여 자가 치유효과 를 볼 수 있는 재료이다. 외부 하중에 의한 변형을 자가치유 효과를 사용하여 회복을 하고자 하는 연구는 계속되어 왔지만 온 도의 변화를 구조물 전체적으로 줘야한다는 많은 불편이 있었다. 따라서 본 연구에서는 이 효과를 증진하여 상온에서도 자가 치유효과를 할 수 있는 초탄성 형상기억합금을 이용한다. 구조물에 있어서의 초탄성 형상기억합금의 능력을 스테인리스강과 함 께 비교하고 비교를 위해 강재가 가장 변형되기 쉬운 형태인 와이어형태로 가공하여 다양한 인장실험을 진행한다. 인장실험의 종류는 총 3가지로 변위를 다르게, 인장속도를 다르게, 선 인장력을 다르게 하는 실험으로 진행된다. 이때의 응력, 변형률간의 그래프를 그리고 잔류변형, 재료의 항복점 및 회복, 에너지 소산과 같은 구조물에 있어서의 재료적 능력을 파악하고 따로 그래 프를 도식화 하여 해석하였다.

손상된 콘크리트 구조물은 적절한 보수 및 보강을 통해 성능과 기능을 회복시켜야 한다. 장기간 공기 중에 노출된 콘크리트는 동결융화 작용으로 균열 및 박리를 일으켜 내부 철근의 부식을 유발하게 되는 주요 요인이 된다. 본 연구에서는 동 결융해 손상을 입은 콘크리트 교각의 FRP 보강의 연성에너지 증가 효과를 분석하였다. 보강 FRP 재료와 보강 높이, 보강 겹수 에 따라 동결융해 손상 콘크리트의 푸쉬오버 매개변수 해석을 수행하여 모멘트 곡률의 연성에너지를 비교 분석하였다. FRP 보 강 높이는 소성 힌지 이상의 높이 보강은 비효율적이며, 동결융해 손상이 커질수록 FRP 보강으로 인한 연성에너지 증가량은 커 지는 것을 확인하였다. 보강으로 인한 연성에너지 증가를 위해서는 고강도 FRP 재료보다는 높은 탄성계수를 갖는 FRP 재료가 효율적으로 나타났다. 또한 각 FRP 재료의 특성에 따라 일정 보강 겹수 이상에서 보강 효과가 나타나는 것을 확인하여 FRP 보 강으로 인한 손상된 콘크리트 교각의 연성에너지를 비교 분석하였다.

PURPOSES : In this study, the results of an intensive field survey of a composite pavement applied to an expressway in Korea are analyzed. The results are intended to be used as basic data for evaluating the composite pavement and for preparing quality control measures through a review and analysis of the change in the state of the tensile bonding strength of the composite pavement. METHODS : To evaluate, repeated field coring and indoor tensile bonding strength evaluations are conducted for five years, and the commonality evaluation of pavement using pavement condition investigation equipment is conducted annually. RESULTS : The results of this study show that the degree of reflective crack generation varies depending on the type of concrete pavement and type of asphalt mixture applied to the intermediate layer, and that the CRCP composite pavement exhibits better initial commonality than the JCP composite pavement. In addition, it is confirmed that the composite cross-section pavement section with MASTIC applied as an intermediate layer shows excellent adhesion performance between the lower concrete layers from the beginning of construction in all sections, as well as satisfied the quality control standards for good pavement and tensile adhesion even after approximately five years of public use. CONCLUSIONS : Based on a follow-up survey of the composite pavement testing sections, it is confirmed that the section constructed with the MASTIC intermediate layer and CRCP satisfies the quality control standards for good pavement conditions and tensile adhesion even after approximately five years of public use.