As the use of nuclear energy has been expanded, issues in a spent nuclear fuel management are raised. Several methods have been proposed and developed to manage spent fuels safely and efficiently. One method is to reduce environmental burden in disposal of spent fuels by decreasing volume of high-level waste. A nuclides management process (NMP) is one example. Through this novel process, it is able to separate highly mobile nuclides (ex. iodine, krypton), high thermal emission nuclides (ex. strontium, barium), and optionally, uranium from spent fuels. Since the NMP is a back-end fuel cycle technology, a reliable safeguards system should be employed in the facility. As international atomic energy agency (IAEA) recommends safeguards-by-design (SBD), it is desirable to investigate an appropriate safeguards approach at a step of technology development. Process monitoring (PM) is a complemental safeguards technology for traditional safeguards technologies which based on mass balance. PM traces nuclear materials indirectly but consecutively by using process parameters such as temperature, pressure, and flow of fluid. These parameters are obtainable by installing appropriate sensors. In a respect of SBD, PM is a promising approach to achieve the safeguards goal, the timely detection of diversion of a nuclear material. However, it is necessary to classify useful process parameters from all available signals which provided from PM in order to properly utilize PM. In this study, we investigated application methods of the PM approach to NMP. NMP consists of several unit processes in series. Firstly, we inspected a principle and a feature of each unit process. Based on the results, we evaluated applicability of the PM approach to each unit process according to effectiveness in enhancing safeguardability. Several unit processes were expected that their safeguards are able to be enhanced by using certain process parameters from PM.

Surveillance plays a crucial role in safeguards. Reviewing surveillance data requires a significant number of inspection manpower. As the number of surveillance cameras increases, the demand for such manpower is expected to grow even more. Recently, in the field of security, there has been a development of deep learning models that automatically detect abnormal events from video images, and their usage is expanding. In this study, we used an AutoEncoder-based semi-supervised learning model, which can detect unexpected abnormal events, to detect anomalies in the UCSDped2 dataset and in simulating safeguards-related event videos taken at Dry Mockup facility of KAERI. To improve the model performance, we transformed the video images into two parts: the appearance part, which are sequences of video image frames, and the motion part, which are the pixel value differences of consecutive video frames. In addition, we added memory module to the bottle neck of the AutoEncoder model, and skip connection to enhance the model performance. To evaluate the model performance, we proposed a new evaluation index, which is adequate to the video images of safeguards surveillance in addition to the widely used AUC (Area Under the ROC Curve).

For deep geological repository of the spent nuclear fuel, the fuel assemblies loaded in the storage cask are transferred to the disposal cask and the operation is performed in the fuel handling hot cell at the fuel re-packaging facility. As the fuel handling hot cell shielding is accomplished by the concrete wall and the viewing glass window, the required shielding thickness was evaluated for both materials. The ordinary concrete is applied to hot cell wall and two kinds of glasses, i.e., single layer of lead glass and double layer of lead glass and borosilicate glass, are considered for the viewing glass window. A bare spent PWR fuel assembly exposed to the environment in the hot cell was considered as the neutron and gamma radiation sources. The neutron and gamma transport calculations were performed using the MAVRIC program of the SCALE code system for the dose rate evaluation. The dose limit of 10 μSv/h is applied as the target dose to establish the required shielding thickness. The concrete wall of 94 cm thickness reduces the total dose rate to 6.9 μSv/h, which is the sum of neutron dose and gamma dose. Penetrating the concrete wall, both of the neutron dose and the gamma dose decrease constantly with shield thickness and the gamma dose is always dominant through whole penetrating distance. Single layer lead glass of 74 cm thickness reduces total dose rate to 6.2 μSv/h. Applying double layer shield glass combined of lead glass and borosilicate glass, the total dose rate reduces to 3.6 μSv/h at same shield thickness of 74 cm. Through the shield glass, gamma dose decreases rapidly and neutron dose decreases slowly compared with those for concrete wall. In result, neuron dose becomes dominant on the window glass shielding. The more efficient dose reduction of double layer glass is achieved by the borosilicate glass’s superior neutron shielding power. Thus, the use of double layer glass of lead glass and borosilicate glass is recommended for the viewing glass of the fuel handling hot cell. Finally, it is concluded that about 1 m thick concrete wall and 75 cm thick viewing glass window are sufficient for the radiation shielding of the hot cell at the spent fuel repackaging facility.

A simulation model was developed for heavy water pre-enrichment and detritiation by the Combined Electrolysis and Catalytic Exchange (CECE) process. In the CECE process, heavy water enrichment and detritiation are based on the principle that concentrated in to water phase through an isotopic exchange reaction between water vapor and hydrogen gas produced by a water electrolysis. An operational analysis for a liquid phase catalytic exchange column was carried out by the model equations, composed of a material balance and combined equilibrium relationships for a scrubbing and catalyst bed, respectively. As a result of simulation, the optimum flow ratio of water to the rising hydrogen gas in contact with the down-coming water was predicted as the key variables in the separation performance analysis at a given feed flow rate and isotopic composition. From a graphical approach based on this model, the operating conditions can be determined within the range where the operating line does not meet the combined equilibrium line before reaching the specified target concentration.

The nuclide management technology for separating high-heat generating/high-mobility/long-lived nuclides from high-level wastes based on the chemical reactions is under development. In order to secure the reliability of nuclear non-proliferation and to implement the effective safeguards, it is necessary to consider the safeguards from the conceptual design phase of the novel technologies. However, there was no experience and research on safeguards for the chemical reaction based nuclide management technology. In order to development the available monitoring techniques for the safeguards of nuclide management technology, the possible diversion scenarios were developed and the material flows of major nuclear materials were analyzed according to the various diversion strategies for each unit process in this study. The diversion strategies in this study is limited to the diversion of nuclear materials according to the change of operational parameters (temperature, chemical reagents, pressures, etc). The nuclear material distribution behaviors under the abnormal conditions were analyzed and compared with normal conditions using the HSC Chemistry. The results will be used to determine the proper signals and feasible techniques to monitor the abnormal operations.

A safety assessment of radioactive waste repositories is a mandatory requirement process because there are possible radiological hazards owing to radionuclide migration from radioactive waste to the biosphere. For a reliable safety assessment, it is important to establish a parameter database that reflects the site-specific characteristics of the disposal facility and repository site. From this perspective, solubility, a major geochemical parameter, has been chosen as an important parameter for modeling the migration behavior of radionuclides. The solubilities were derived for Am, Ni, Tc, and U, which were major radionuclides in this study, and on-site groundwater data reflecting the operational conditions of the Gyeongju low and intermediate level radioactive waste (LILW) repository were applied to reflect the site-specific characteristics. The radiation dose was derived by applying the solubility and radionuclide inventory data to the RESRAD-OFFSITE code, and sensitivity analysis of the dose according to the solubility variation was performed. As a result, owing to the low amount of radionuclide inventory, the dose variation was insignificant. The derived solubility can be used as the main input data for the safety assessment of the Gyeongju LILW repository in the future.

This study was designed to assess the possibility of using medicinal plant extracts as β-lactamase inhibitors to control antibiotic-resistant Staphylococcus aureus. The susceptibilities of S. aureus ATCC 15564 (SAWT), ciprofloxacininduced S. aureus ATCC 15564 (SACIP), oxacillin-induced S. aureus ATCC 15564 (SAOXA), and clinically-isolated S. aureus CCARM 3008 (SACLI) to ampicillin were determined in the absence and presence of medicinal plant extracts, including Cleyera japonica (CJ), Carpinus laxiflora (CL), Euphorbia helioscopia (EH), Euscaphis japonica (EJ), Oenothera erythrosepala (OE), and Rosa multiflora (RM). The phenotypic change in the clear inhibition zones around ampicillin disc was observed for SAWT, SACIP, and SAOXA, indicating the production of ampicillinase. Compared to the controls, the MICs of ampicillin against SAWT, SACIP, and SAOXA were decreased from 4 to 0.5 ㎍/mL in the presence of CL, 16 to 4 ㎍/mL in the presence of RM, and 32 to 2 ㎍/mL in the presence of CL, EH, and RM, respectively. The medicinal plant extracts, OE, EJ, and CL, effectively inhibited the β-lactamase activities of SAWT (78%), SACIP (57%), and SAOXA (76%) when compared to the control. This results suggest that the medicinal plant extracts can be used as BLIs to control the antibiotic-resistant S. aureus.

In this study, we first measured the malmquist productivity index by DEA among the Korean public firms. Second, there are 12 public corporations whose productivity (MPI) has decreased compared to 2014. This is mainly because of a decrease in productivity, as well as a decrease in the technical efficiency change index (TECI), impacted by the internal environment, and the increase in productivity because of an increase in the technology change index (TCI) impacted by the external environment. Finally, the analysis of the impact on the management assessment scores showed that the productivity (MPI), scale efficiency (CRS), size of sales, operating profitability, and total capital investment efficiency are significantly related (+), except for the asset turnover, which is a static financial ratio. Meanwhile, the management evaluation scores between the high-productivity public corporations and low-performing public corporations were significantly discriminating. Thus, it is confirmed that the nation's state-run companies must manage their MPIs in a time series to score high in management evaluation.

Site characterization for decommissioning Kori Unit 1 is ongoing in South Korea after 40 years of successful operation. Kori Unit 1’s containment building is assumed to be mostly radioactively contaminated, and therefore radiation exposure management and detailed contamination investigation are required for decommissioning and dismantling it safely. In this study, site-specific Derived Concentration Guideline Levels (DCGLs) were derived using the residual radioactivity risk evaluation tool, RESRAD-BUILD code. A conceptual model of containment building for Kori Unit 1 was set up and limited occupational worker building inspection scenario was applied. Depending on the source location, the maximum contribution source and exposure pathway of each radionuclide were analyzed. The contribution of radionuclides to dose and exposure pathways, by source location, is expected to serve as basic data in the assessment criteria of survey areas and classification of impact areas during further decommissioning and decontamination of sites.

In this study, the current state of management efficiency of ocean carriers in Korea and the factors affecting them were analyzed. The purpose of this research is to enhance global competitiveness of ocean carriers by presenting suggestions that can improve management efficiency based on the analysis results. The measurement of management efficiency was made using the DEA model. The results of testing the adequacy of the input and output variables used are as follows. Appropriate inputs are total assets, cost of goods sold, charter expenses, sales and general management expenses, and interest expenses. Appropriate variables are sales, operating income ,and operating cash flow. According to the analysis results of the DEA model by these variables, inefficient carriers (78%) are nearly four times more than efficient carriers(22%). However, container carriers have the most improved management efficiency compared to 2016 and 2017. According to the panel regression analysis, the charter rate has the greatest negative impact on efficiency (CRS), and the debt rate has a significant negative impact. Thus, it appears that reducing the charter size and the debt-to-sale rate facilitate improvement of the management efficiency of ocean carriers. Additionally, the pre-sales tax return rate, value added rate, total asset turnover rate, and the scale variable and interest coverage rate have a positive (+) effect. Thus ocean carriers should restore their global competitiveness by improving management efficiency by securing stable cargoes increasing sales profitability from the cost management perspective, increasing productivity, and enhancing the efficiency of their total assets through efficient fleet management.

This study examined whether the English proficiency was a factor to determine how Korean EFL university students use language copied from a source without attribution. The unattributed copying from a source was analyzed using a quantitative measurement, and a questionnaire was administered to examine the students' perception of plagiarism. The results showed that the total amount of textual borrowing and the length of strings of words borrowed from a source demonstrated a significant relationship with proficiency levels. The participants' language proficiency also influenced their perceptions regarding plagiarism. The differences observed between the two groups in perceiving plagiarism suggest that students with low English proficiency may be somewhat less aware that their heavy reliance on direct copying of a source could be regarded as unacceptable in academics than those with high English proficiency. Implications of these findings are discussed focusing on preventing plagiarism.

According to the results of the management evaluation of the nation’s public firms over the past seven years, the rating of the port corporation is generally insufficient. According to the results of the seven-year study 2011-2017, the average debt ratio of the port corporation was 34.5%, two to three times lower than that of the general public company, the operating profit ratio of sales was three times higher, and the value added per person was 1.6-1.9 times better. However, the aggregate score and grade were generally low, with 4.1% of the total number of employees of the general public corporation, 10% of the average total assets, and 1% of the average sales volume. The distributed analysis results and panel return analysis results show that the size significantly impacts the overall score and grade. Additionally, major business standards such as port volume, not controlled by the port corporation, appear to have a decisive influence on the low grade of the port corporation. Thus, it appears that improvement and supplementation of key business indicators of port construction are urgently needed in the management evaluation system, which can be properly controlled.

본 논문의 목적은 20세기 영국 모더니즘 최고 시인 엘리엇과 프랑스 상징주의 최고 시인 발레리의 1926-1929년 사이의 관계를 전기비평 관점에서 조명하는 것이다. 이 논문은 주로 『T. S. 엘리엇의 서한집』 3권 (2012)과 4권(2013)에 수록된 서신들에 나타난 『크라이티어리언』 편집인 이자 페이버앤가이어 이사인 엘리엇이 1927년 런던의 리셉션 식장에서 발레리와의 짧은 조우로 불쾌한 감정을 느꼈지만, 발레리의 친구 윌리 엄 맥코즈랜드 스튜어트와 스튜어트의 친구 토마스 맥그리비의 발레리 산문과 운문 번역문 출판에 크라이티어리언출판사 대신에 페이버앤가이어, 호가스출판사, 조나산케이프출판사가 협조하도록 적극적으로 지원하 면서 중재하고 있다. 엘리엇의 서신을 통한 집요한 노력 덕택으로 맥그 리비의 번역본 『레오나르드 다빈치 방법 입문』이 1929년 존 로드커에서, 스튜어트의 번역본 『건축가 에우팔리노스』가 1932년 호가스출판사 가 아닌 옥스퍼드대출판부에서 출간된다. 요컨대, 4년 기간에 걸친 엘리 엇과 발레리 번역가들, 호가스출판사의 레너드 울프 출판인, W. B. 예이츠와 엘리엇의 상호 친구인 토마스 스터지 무어 시인이자 비평가 및 기 타 문인들과의 수많은 영불(英佛) 서한들은 특히 발레리 작품의 세계적인 보급을 위한 영역(英譯) 출판에서 엘리엇과 발레리 이 두 거장들의 신뢰할 만하고 존경스런 우정을 강력히 제시하고 있다.