The radwaste facility management team is preparing for clearance of 4 MCAs in The Radwaste Form Test Facility (RFTF). The targeted waste was used for clearance level radioactive waste sample analysis and has been used for this purpose since the early 2000s. Due to the characteristics of clearance level radioactive waste, the concentration of radioactivity is very low and MCA is used with Marinelli beakers the possibility of contamination is low. Moreover, the radiation detector should not be contaminated with radioactive materials, it should be less than the clearance level. These detectors were considered surface contamination materials. To detect the contaminated spot of each material, we scanned the whole surface of a material with a gamma survey meter. After that, we took a sample from 1×1 m2 and a total of 30 samples from each MCA. The wiped filter paper was analyzed with alpha, beta low background counting systems. The results of the analysis of the smear sample of total alpha and beta nuclide radioactivity were less than MDA (α: 2.88×10−5 Bq·cm−2, β: 3.07×10−5 Bq·cm−2). The major nuclide in this facility is Co-60 and Cs-137 therefore we analyzed gamma nuclide activity with HPGe. The maximum specific activity was Co-60: 2.31×10−5 Bq·cm−2, Cs-137: 1.96×10−6 Bq·cm−2. If it is satisfied with the clearance criteria, detectors will be reused at the Radioactive Waste Treatment Facility (RWTF) room # 7251 uncontrolled area.

Radioactive materials emitted from nuclear accident or decommissioning cause soil contamination over wide areas. In the event of such a wide area of contaminated soil, decontamination is inevitable for residents to reside and reuse as industrial land. There are many ways to decontaminate these contaminated soils, but in urgent situations, the soil washing, which has a short process period and relatively high decontamination efficiency, is considered the most suitable. However, the soil washing process of removing fine soil and cesium by using washing liquid as water and adding a flocculating agent (J-AF) generates slurry/sludge-type secondary waste (Cs-contaminated soil + flocculating agent). Since this form of sludge contaminants cannot be disposed, solidification is needed using an appropriate solidification agent to treat wastes for disposal. Therefore, this study devised a treatment method of contaminated fine soils occurring after the soil washing process. This investigation prepared the simulated wastes of contaminated fine soils generated after the soil washing, and pelletized the samples using a roll compactor under the optimum operating conditions. The optimum conditions of the device were determined in the pre-test. Roll speed, feeding rate, and hydraulic pressure were 1.5 rpm, 25 rpm, and 28.44 MPa, respectively. The waste forms were manufactured by incorporating created pellets (H 6.5 × W 9.4 mm) using polymers as solidification agents. Used polymers were main ingredient (YD-128), hardener (G-1034), and diluent (LGE). The optimum mixing ratio was YD-128 : G-1034 = 65 : 35 phr, and LGE was added in an amount of 10wt% of the total mixture. To confirm the disposal suitability of the manufactured waste forms, characterization evaluation was carried out (compressive strength, thermal cycling, immersion, and leaching test). Characterization evaluation revealed a minimum compressive strength of 23.1 MPa, far exceeding 3.44 MPa of the disposal facility waste acceptance criteria. Compressive strength increased to the highest value of 31.90 MPa after immersion test. To examine leaching characteristics, the pH, Electrical Conductivity (EC) and leachability index (􀜮􀯜) of leachates were identified. As results, pH and EC consistently increased or remained constant with leaching time. The average of Co, Cs and Sr nuclides was 17.76, 17.38 and 14.04, respectively, exceeding the value of 6 in the waste acceptance criteria. Effective waste treatment/ disposal can be achieved without increasing volumes of sludge/slurry by enhancing the technique of this research by performing additional studies in the future.

During the treatment of spent nuclear fuel, radioactive iodine is generated in a liquefied or gaseous form in a specific process. In the case of iodine 129, it is a long-lived nuclide with a very long halflife and has high groundwater mobility under repository conditions. Despite showing a low radioactivity value, research on the management of radioactive iodine from a long-term perspective is continuously being performed. Although research has been conducted using borosilicate glass as a medium for solidifying iodine, compatibility of I in borosilicate glass is very small and the volatility is high in the solidification process. So it is not suitable as a solidified substance of iodine. Therefore, studies on other solidification media to replace them are continuously being conducted. Our research team tried to develop a new medium that can contain iodine in a solidified body stably through a simple heat treatment process and can improve problems such as volatility and waste loading. Iodine is captured as AgI in the Ag ion-exchanged zeolite. So, TeO2, Ag2O, and Bi2O3 having a high AgI loading rate were used as main components. It was named TAB after taking the first letter of each element. In previous studies, the physical properties, structure, and chemical stability of TAB materials were confirmed. PCT (Product Consistent test) was performed to confirm chemical stability. It is mainly used to compare the chemical stability of glass materials with other glass materials, but there are limitations in evaluating the long-term chemical stability of materials. In this experiment, we tried to evaluate the long-term stability of TAB and compare it with borosilicate, which is conventionally used to treat radioactive waste. In addition, we tried to understand the leaching behavior inside the TAB medium. For this purpose, ASTM C1308 test was performed for 365 days, and distilled water and KURT groundwater were used as leachates to examine the effect of ions in the groundwater on the solidified body. To analyze the leaching behavior, ICP-MS and ICP-OES analyses were performed, and the cross-section of the sample after leaching was observed through SEM.

Radioactive Cesium is fission products of spent nuclear fuelwith high heat generating nuclide, having a 30 years half-life. Particularly, it is important to make stable waste form because Cs-137 have high solubility and mobility at ground water. The ceramic waste form has higher thermal and structural stability and lower solubility than glass and cement waste form. Various ceramic waste forms for Cs immobilization have been researched such as aluminosilicate (CsAlSi2O6), phosphate (CsZr2(PO4)3), titanate (CsxAlxTi8-XO16) and CsZr0.4W1.5O6. Cs pollucite is incorporated radio-Cesium to aluminosilicate framework by inorganic ion-exchange with zeolite. Therefore, it is an extremely stable structure. In previous study, we are prepared Cs pollucite pellet with various ratio of Cs precursor/matrix materials, and attempted to evaluate applicability as ceramic waste form. Cs pollucite is produced by mixing Mullite and SiO2 obtained by heat treatment Kaolinite with Cs2CO3 in ratios of 0.5, 0.6, 0.7, 0.8. Optimized ratio was 0.5 revealed single pollucite phase and the others exhibited CsAlSiO4 phase with pollucite. Cs pollucite of ratio 0.5 was pelletized under various conditions and evaluated performance as waste form. herein, the pellets were cracked on surface and edges broken. Therefore, Cs pollucite having high ratio of matrix materials contained Si and Al was prepared and pelletized, and then waste form was evaluated. The Cs pollucite powder is ratio of Cs precursor/matrix materials were 0.1, 0.2, 0.3, 0.4. Pollucite powder was mixed with 1.5, 2.0wt% Polyvinyl alcohol as binder, and dried at 70°C for overnight. Afterward, these powders obtained were pressed using punch-die apparatus at 50, 100 bar for 1 hour and the pellets with about dia. 25 mm and height 10 mm was acquired. These pellets were sintered at 1,400°C for 5 hours. Subsequently, the waste forms were evaluated physicochemical test such as compression strength, thermal conductivity, thermal expansion and leaching properties analysis.

Garnet is one of the promising ceramic waste forms for immobilizing radioactive wastes. It has an A3 [VIII]B2 [VI]T3 [IV]O12 structure, so it can accommodate various cations of different sizes and coordination. Silicon usually occupies the centers of the tetrahedron structural site (T[IV]O4) in natural garnet. However, substitution of the T-site with iron, which has a relatively large ionic radius, causes the expansion of a unit cell volume of garnet and allows the incorporation of large cations such as actinides at other sites. Relatively few leaching data have been reported for ferrite garnet waste forms to date. In this study, we synthesized gadolinium-iron-garnet and evaluated the leaching property using cerium as a surrogate for actinide elements. The test specimens were made by cold pressing and sintering process. Three different standard leaching tests were performed as follows. The PCT-A (ASTM C1285) was performed for 7 days at 90°C to the crushed sample (0.149 to 0.074 mm). The ANSI/ANS-16.1 standard leach test was performed at ambient conditions for 5 days with constant replacement of leachate. Finally, the MCC-1 (ASTM C1220) test was performed for 28 days at 90°C with different types of leachants such as ultrapure water, brine, and silicate water. The last two leaching tests were conducted on monolithic specimens. After the end of the test, leachate was analyzed by inductively coupled plasma mass spectroscopy (Agilent, ICP-MS 7700S).

To reduce the environmental burden caused by the disposal of spent nuclear fuel and maximize the utilization of the repository facility, waste burden minimization technology is currently being developed at the Korea Atomic Energy Research Institute (KEARI). The technology includes a nuclide management process that can maximize disposal efficiency by selectively separating and collecting major nuclides in spent nuclear fuel. In addition, for efficient storage facility utilization, the short-term decay heat generated by spent nuclear fuel must be removed from the waste stream. To minimize the short-term thermal load on the repository facility, it is necessary to separate heat generating nuclides such as Cs-137 and Sr-90 from the spent fuel. In particular, Sr-90 must be separated because it generates high heat during the decay process. KAERI has developed a technology for separating Sr nuclides from Group II nuclides separated through the nuclide management process. In this study, we prepared Sr ceramic waste form, SrTiO3, by using the solid-state reaction method for long-term storage for the decay of separated Sr nuclides and evaluated the physicochemical properties of the waste form. Also, the radiological and thermal characteristics of the Sr waste form were evaluated by predicting the composition of Sr nuclides separated through the nuclide management process, and the estimation of centerline temperature was carried out using the experimental thermal data and steady state conduction equation in a long and solid cylinder type waste form. These results provided fundamental data for long-term storage and management of Sr waste.

The fabrication of waste forms with high thermal and structural stability is an essential technology for the safe management and disposal of radioactive wastes. In particular, the thermal characteristics of waste forms containing high heat-generating nuclides such as Cs and Sr can be used for the optimized design of the waste form to secure its thermal safety, and they also provide basic design data for the safe management of canisters, storage systems, and repositories. The Korea Atomic Energy Research Institute is actively developing processes and equipment for fabricating various types of high-level wastes into a stable glass or ceramic waste form. In previous research related to the thermal analysis of the waste form, a relatively simple analysis was performed by using the analytic solution of the one-dimensional steady-state heat conduction equation considering the decay heat properties of the waste. As a specific application study, the optimized diameter of the cylindrical glass waste form was proposed by evaluating the centerline temperature of the waste form. In this study, we extended previous research by introducing a more complicated model, and the main results are summarized as follows. First, an analytical solution was derived by applying the temperaturedependent thermal conductivity expressed in the general form of polynomial function to the onedimensional heat conduction problem previously studied. Second, the two-dimensional axisymmetric steady-state heat conduction problem with a more realistic cylinder model with finite length was modeled and solved by using the finite element method via Matlab’s PDE (partial differential equation) toolbox. Third, thermal analysis was performed on the SrTiO3 waste form, selected as a stable form of strontium nuclide, using the developed analytical and numerical methods. The differences in the temperature distribution and computation time were evaluated through a comparative study of both solutions. Although the problem considered in this study could easily be solved by using commercial CFD software such as ANSYS or SolidWorks, a code-based program was developed to facilitate parametric design study in conjunction with optimization algorithms. The analysis results could be used to evaluate the thermal stability of waste form and to optimize the shape and size of the waste form in consideration of the design constraints of storage systems or repositories.

As the largest written Chinese dictionary in the Joseon Dynasty, “Gujin Shilin” contains a wealth of Korean vulgar words. This paper takes the Korean Kanji Words in “Gujin Shilin” as an example, analyzes the Korean common characters used in the entry, and summarizes the characteristics of the common characters in the inheritance of “Liushu”, such as associative compounds, pictophonetic characters, and phonetic loan characters, as well as the simplification of the form, the symbolization of the components, and the components of the common characters. The variation law of functionalization and reconstruction of pronunciation and meaning is beneficial to the research on the spread and development of popular characters outside the territory.

빅 데이터, 알고리즘, 인공지능, 블록체인, 메타버스 및 스마트계약과 같이 21세기의 기술혁신은 기존의 주주총회 개최방법의 효율성과 공정성 에 의문을 제기하게 만들었고, 경영진에게 새로운 역량이나 기술을 습득 하거나 보유할 것을 요구하고 있으며, 기업 내에서 기존에 의사결정을 내리던 자들에게 보다 효율적인 방식으로 기업을 운영할 수 있는 도구를 제공하고, 기업 내에서 누가 실질적인 의사결정권을 가져야 하는지를 결 정하는 균형추를 바꾸어 놓고 있으며, Corona-19 팬데믹은 가상주주총 회 도입 시기를 우리가 예상했던 것보다 훨씬 더 빠르게 앞당겨 놓았다. 기업지배구조의 기본 테마 중 하나는 기업의 경영진에게 부여되는 광 범위한 재량권과 주주들이 경영진에 대해 책임을 추궁할 수 있는 권한 간에 균형을 맞추는 일이다. 따라서 이글은 새로운 기술들이 어떻게 주 주총회를 주주민주주의의 시금석으로 부활시키고, 어떻게 주주들이 기업 경영에 관여할 수 있는 새로운 길을 열 수 있는지, 기업 내 구성원들의 역할 및 권한과 책임분배에서 어떤 역할을 수행할 수 있는지, 공동의사 결정 비용을 감소시키고 보다 효율적인 의결권 행사절차를 가능케 함으 로써 주주총회의 역할을 강화시킬 수 있는지 등에 대한 것들이다. 그런 데 가상주주총회에 대해 비판적 견해도 많지만 가상주주총회는 주주참여 와 접근성을 높이고, 주주와 이사 및 경영진 간의 상호작용을 활발하게 하며, 탄소 발자국을 줄일 수 있고, 비용을 절감할 수 있는 등 많은 장점 을 가지고 있다, 특히 개인투자자들이 적극적으로 주주총회에 참석하여 건설적인 의견을 제시할 경우, 효율적인 의사결정이 이루어질 수 있고, 이는 회사의 실적향상으로 이어질 수도 있으므로 형해화 되었다는 비판 을 받던 주주총회가 본연의 기능을 회복할 수 있을 것이라는 기대는 가 상주주총회가 갖는 최고의 장점이 아닐까 하는 생각이 든다. 그러나 이 제도가 우리나라에 온전하게 도입되기 위해서는 학계의 비 판적 견해와 갈라져 있는 견해들을 수렴하여 바람직한 해결책을 찾고, 특히 우리보다 앞서 많은 논의가 이루어지고 실무경험이 풍부한 외국의 사례들을 심도 있게 연구하여 바람직한 기업지배구조 개선을 위한 입법 방향을 제시할 수 있어야 할 것이다. 그리고 주식회사 구성원들 간에 보 다 활발한 상호작용이 이루어질 수 있는 메타버스 기술과 의결권 행사 데이터에 대한 위조와 변조가 현실적으로 어려워 보안성이 높기 때문에 의결권 행사의 신뢰성을 확보할 수 있는 블록체인 기술도 아울러 도입할 것을 제안한다.

1970년대 북한 조선화 형식론의 주요 특징으로는 기법과 수법의 상위개념으로서 ‘화법’ 개념의 정립, 색채의 주관적 인식(일반성)과 객관적 지각(개별성)을 포괄하는 개념으로서 ‘제 색(본색)’ 개념의 부상, 예술적 형상화의 높이에 올라선 ‘예술적 필치’ 개념에 대한 강조 등 으로 요약할 수 있다. 1970년대 북한 조선화 형식론은 대립하는 것들의 중재, 또는 갈등의 봉합을 추구했다. 그들은 ‘화법’, ‘제색(본색)’, ‘예술적 필치’ 등을 내세워 선과 색, 본색과 반사색, 몰골법과 구륵법 등 대립으로 이끌어지기 쉬운 것들을 담론 체계 안에 효율적으로 통합하고자 했다. 그들은 이것이 조선화의 개조발전과 현대화의 길이라고 믿었다. 그러나 이 렇듯 조율과 중재, 봉합과 화해를 지향하는 개념들은 차이들, 곧 서로 다른 입장들이 경쟁하 면서 새로운 대안을 모색하는 담론장의 역동성을 약화시키는 결과를 초래했다. 1970년대에 구축된 조선화 형식체계는 이후 큰 변화 없이 유지되면서 조선화 창작과 수용에 절대적인 영 향력을 행사했다. ‘화법’, ‘제색’, ‘필치’ 등의 개념들은 모두 조선화를 제작하는 예술가들의 능동적 관여를 강조했지만 그 관여는 언제나 지배체제의 이념이 정해준 길을 따라야 했다. 그런 의미에서 1970년대 조선화 형식론은 궁극적으로 형식 문제를 이념 문제에 종속시키는 방향으로 진행됐다고 말할 수 있다.

전자 및 화학 산업의 초순수 생산 및 원자력 발전소의 부식 제어를 위해 이온교환 수지탑의 성능 파악이 필수적이다. 따라서 본 연구에서는 4종의 H 및 ETAH 형 양이온 교환수지가 채워진 양이온 및 혼상 이온교환수지탑에 미량의 NaCl를 포함하는 에탄올아민(ETA) 및 암모니아(NH3) 용액을 주입하여 양이온 파과특성을 조사하였다. 조사 결과, 주성분인 ETAH+ 및 NH4 +와 달리, 미량성분인 Na+는 (이론적교환용량의 3배 이상) 시험기간 동안 수지탑 출구에서 파과 및 오버슈팅 현상이 나타나지 않았다. H형 수지탑의 파과현상은 ETAH+ 및 NH4 +가 순서대로 일어났고, 오버슈팅은 NH4 +가 파과할때 ETAH+에 대해서 발생했다. 파과영역의 너비로 결정되는 상대적 선택도는 NH4 +가 ETAH+보다 최대 51.5 % 더 높았다. 유입수 Na+ 농도가 높을수록, 선택도는 감소하고 오버슈팅 현상은 증가하였다. 이온교환 수지의 고유 특성을 개선하여 감소시킬 수 있는 Na+ 누출은, ETAH형에서 높았고 4종의 양이온수지에 대해 동일하지 않은 것으로 조사되었다.

This study aims to develop a form-finding algorithm for a single-layered pneumatic membrane. The initial shape of this pneumatic membrane, which is an air-supported type pneumatic membrane, is to find a state in which a given initial tension and internal pneumatic pressure are in equilibrium. The algorithm developed to satisfy these conditions is that a nonlinear optimization problem based on the force method considering the deformed shape is formulated, and, it’s able to find the shape by iteratively repeating the process of obtaining a solution of the governing equations. An computational technique based on the Gauss-Newton method was used as a method for obtaining solutions of nonlinear equations. In order to verify the validity of the proposed form-finding algorithm, a single-curvature pneumatic membrane example and a double-curvature air pneumatic membrane example were adopted, respectively. In the results of these examples, it was possible to well observe the step-by-step convergence process of the shape of the pneumatic membrane, and it was also possible to confirm the change in shape according to the air pressure. In addition, the calculation results of the shape and internal force after deformation due to initial tension, air pressure, and self-weight were obtained.

초고강도 섬유보강 콘크리트 데크플레이트는 높은 콘크리트 압축력과 섬유에 의한 휨인장력의 우력으로 동바리 지지없이 얇은 두께의 데크플레이트로 고정하중과 작업하중을 견딜 수 있는 강성을 가지고 있다. 본 연구는 슬래브 두께, 섬유의 종류와 혼입률, 철근 및 GFRP를 변수로 휨실험을 수행하였다. 40mm∼50mm 두께의 120MPa 초고강도 콘크리트에 강섬유를 체적 대비 1.5% 이상을 혼입한 데크플레이트로 슬래브의 자중과 작업하중을 부담할 수 있으며, 철근을 보강하면 내하력이 더욱 증진 되고 연성거동을 하는 데크플레이트 특성을 가지는 것을 검증하였다.