Wolsong Unit 1, a domestic heavy water reactor nuclear power plant, was permanently shut down in December 2019. Accordingly, Wolsong Unit 1 plans to prepare a Final Decommissioning Plan (FDP), submit it to the government by 2024, receive approval for decommissioning, and begin full-scale decommissioning. One of the important tasks in the decommissioning of Wolsong Unit 1 is to determine the decommissioning strategy. It is necessary to decide on a decommissioning strategy considering various factors and variables, secure the technical background, and justify it. The selection of a decommissioning strategy is best achieved through the use of formal decisionmaking assistance techniques, such as considerations related to influencing factors. It is very important to understand the basic decommissioning strategy alternatives and whether sufficient consideration has been given to situations where only a single unit is permanently shut down in a multi-unit site like Wolsong Unit 1, while the remaining units are in normal operation. As a process for selecting a decommissioning strategy, first, all considerations that could potentially affect decommissioning presented in the KINS Decommissioning Safety Review Guidelines were synthesized, influencing factors to be used in the decision-making process were determined, and the concept was defined. In order to select the most appropriate decommissioning strategy by considering various evaluation attributes of possible decommissioning alternatives (immediate dismantling and delayed dismantling), the Wolsong Unit 1 decommissioning strategy was evaluated by reflecting the AHP decision-making technique.

The decommissioning of domestic Nuclear Power Plants (NPPs) in Korea is expected to begin with the Kori-1, which was permanently shutdown in 2017. In addition, Wolsong-1 has been also permanently shutdown, and another type will be the decommissioning project following Kori-1. KHNP is promoting operation and decommissioning projects as the owner of NPPs, and the Central Research Institute (CRI) has been developing a Final Decommissioning Plan (FDP) for the decommissioning license document. The FDP consists of 11 major chapters in the order of overview of the project, characteristic evaluation, safety assessment, radiation protection, decontamination & dismantlement activities, waste management, etc. The contents described in each chapter are individual chapters, but there are also parts that consider the connection with other chapters. The CRI, which develops the FDP for the first decommissioning project in Korea, has spent a lot of time and effort considering this and has been proceeding through trial and error until the present stage. Therefore, this study aims to explain the current status of FDP, a license document for domestic decommissioning projects, and the link between major input data in major chapters. It can be said that System, Structure, and Components (SSCs) subject to dismantling are considered as the scope of FDP. Chapters that perform estimations on these dismantling targets may include safety assessments, exposure dose assessments for workers and residents, and waste inventory assessments. Therefore, an important part of performing the estimation works is to consider the entire scope of decommissioning activities, and as a way, it can start from data based on the inventory data. After generating the inventory data, the waste treatment classification for the inventory is designated by reflecting the results of the characterization. In addition, for cost estimation, the cost of decommissioning project is predicted by inputting some data (i.e., UCF) such as work process, number of workers, and time required for each item with data reflected in quantity and characterization. After that, based on these inventory, characterization, and UCF data, accident scenarios and industrial safety evaluation are performed for the safety assessment. The worker exposure dose is estimated by considering the dose rate of the workspace with these data. In the case of the amount of waste, the final amount of waste is estimated by considering the factors of reduction and decontamination. In summary, the main estimation contents of FDP are evaluated by adding elements required for the purpose of each chapter from data combined with inventory, characterization, and UCF, so the contents of these chapters are based on the logic of considering the entire scope of decommissioning in common.

The influence of MgO addition on the densification and microstructure of alumina (Al2O3) was studied. Compacted alumina specimens were manufactured using ball-milling and one-directional pressing followed by sintering at temperatures below 1700oC. Relative density, shrinkage, hardness, and microstructure were investigated using analytical tools such as FE-SEM, EDS, and XRD. When the MgO was added up to 5.0 wt% and sintered at 1500oC and 1600oC, the relative density exhibited an average value of 97% or more at both temperatures. The maximum density of 99.2% was with the addition of 0.5 wt% MgO at 1500oC. Meanwhile, the specimens showed significantly lower density values when sintered at 1400oC than at 1500oC and 1600oC owing to the relatively low sintering temperature. The hardness and shrinkage data also showed a similar trend in the change in density, implying that the addition of approximately 0.5 wt% MgO can promote the densification of Al2O3. Studying the microstructure confirmed the uniformity of the sintered alumina. These results can be used as basic compositional data for the development of MgOcontaining alumina as high-dielectric insulators.

As an initial part of Kori-1 & Wolsung-1 Unit decommissioning planning, a characterization plan is developed to define the nature, extent and location of contaminants, determine sampling locations and protocols, determine quality assurance objectives for characterization, and define documentation requirements. The actual characterization of a facility is an iterative process that involves initial sampling according to the characterization plan, field management (such as labeling, packaging, storing, and transport) of the samples, laboratory analysis, conformance to the data quality objectives (DQOs), and then identifying any additional sampling required, refining the DQOs, and modifying the characterization plan accordingly. The final product of the facility characterization is a document that describes the type, amount, and location of contaminants that will require consideration and removal during the decommissioning operations sufficient to prepare a decommissioning plan. In this study, implementing a characterization plan, developed in accordance with this standard, will result in obtaining or deriving the above information.

Kori Nuclear Power Plant Unit 1, which began operating in 1978, is Korea’s oldest commercial nuclear reactor. The reactor was permanently shut down in June 2017, and now the decommissioning process has begun. The decommissioning process will generate a significant amount of waste that requires appropriate management to minimize the impact on the environment and human health. And the waste routing, i.e. the activities and logistics for managing the material generated, is a key point in a decommissioning project. It determines the routes from the material inventory to the envisaged material end states. In this study, we review on several factors for the selection of the waste routes in a decommissioning project. In terms of sustainability, the ‘waste hierarchy’ should be applied to routing materials from nuclear facilities. According to the waste hierarchy, the preferred end state is reuse or recycling of the waste as material or, more preferably, the avoidance of waste generation. In addition, treatments (such as decontamination and thermal treatment) that can reduce the volumes requiring disposal as radioactive waste should be considered. Another important parameter is the need to secure availability and capacity of waste routes. Short-term bottlenecks or any delay in the removal of the waste from the site often has an impact on other site activities. If possible, at least two alternative waste routes should be identified for the main categories of waste and kept available throughout the decommissioning project. All routes should be direct to the material end state if possible, but it is more important that waste is removed from the site so that other site operations are not impeded.

This paper considers a joint problem for blood inventory planning at hospitals and blood delivery planning from blood centers to hospitals, in order to alleviate the blood service imbalance between big and small hospitals being occurred in practice. The joint problem is to determine delivery timing, delivery quantity, delivery means such as medical drones and legacy blood vehicles, and inventory level to minimize inventory and delivery costs while satisfying hospitals’ blood demand over a planning horizon. This problem is formulated as a mixed integer programming model by considering practical constraints such as blood lifespan and drone specification. To solve the problem, this paper employs a Lagrangian relaxation technique and suggests a time efficient Lagrangian heuristic algorithm. The performance of the suggested heuristic is evaluated by conducting computational experiments on randomly-generated problem instances, which are generated by mimicking the real data of Korean Red Cross in Seoul and other reliable sources. The results of computational experiments show that the suggested heuristic obtains near-optimal solutions in a shorter amount of time. In addition, we discuss the effect of changes in the length of blood lifespan, the number of planning periods, the number of hospitals, and drone specifications on the performance of the suggested Lagrangian heuristic.

This study investigated the regenerative and healing effect of spirulina on corneal epithelial injury by acid burn in zebrafish. Corneal epithelium of adult zebrafish was evaluated at 0, 12, 24, 48 h after acid burn injury with or without immersion with 0.02 and 0.04 mg/mL of spirulina water extract. The pathological changes of corneal epithelium were assessed by light microscopy. Gene and protein expressions of proliferating cell nuclear antigen (PCNA), matrix metalloproteinase (MMP) 9 and MMP13 were determined by immunohistochemistry or real-time PCR. Corneal epithelium was denuded totally after acid burn and gradually regenerated. PCNA-positive cells significantly increased in spirulina treated group. MMP9 and MMP13 mRNA transcripts were significantly decreased in spirulina treated groups. In conclusion, spirulina has regenerative and healing properties by increased keratocyte proliferation, and inhibited extracellular matrix degradation during the regeneration process of corneal epithelial injury by acid burn in zebrafish.

For electrodes in electrochemical double-layer capacitors, carbon nanofibers (CNFs) were prepared by thermal treatment of precursor polymer nanofibers, fabricated by electrospinning. Poly(acrylonitrile-co-vinylimidazole) (PAV) was employed as a precursor polymer of carbon nanofibers due to the effective cyclization of PAV polymer chains during thermal treatment compared to a typical precursor, polyacrylonitrile (PAN). PAV solutions with different comonomer compositions were prepared and electrospun to produce precursor nanofibers. Surface images obtained from scanning electron microscopy showed that their nanofibrous structure was well preserved after carbonization. It was also confirmed that electrospun PAV nanofibers were successfully converted to carbon nanofibers after the carbonization step by Raman spectroscopy. Carbon nanofiber electrodes derived from PAV showed higher specific capacitances and energy/power densities than those from PAN, which was tested by coin-type cells. It was also shown that PAV with an acrylonitrile/vinylimidazole composition of 83:17 is most promising for the carbon nanofiber precursor exhibiting a specific capacitance of 114 F/g. Their energy and power density are 70.1 Wh/kg at 1 A/g and 9.5 W/kg at 6 A/g, respectively. In addition, pouch cells were assembled to load the higher amount of electrode materials in the cells, and a box-like cyclic voltammetry was obtained with high capacitances.

Wikstroemia ganpi grow the southern coastal regions in Korea, small population and are classified as a critically endangered species. The majority of habitats are located near forest paths and reservoirs at the edge of mountains, indicating that there is considerable human interference and severe fragmentation of populations, as well as damage to individuals as a result of forest fires and soil erosion. We evaluated the genetic diversity in populations, genetic differentiation between populations, and genetic structure to provide data to support the conservation of W. ganpi. W. ganpi populations showed lower genetic diversity(mean level: P.95=36%, S.I=0.170, h=0.113) and higher genetic differentiation(40%) between populations than other species with similar characteristics did. And the among population gene flow(Nm) was highly restricted at 0.87. The four populations revealed that there were fixed alleles in the different loci of each population. This result can be explained by the effects of genetic drift. Structure analysis and the PCA results were more indicative of separate groups than a genetic structure that was linked to populations. This reflects the high level of genetic differentiation between populations and the unique alleles within each population. As a result, lower genetic diversity and higher genetic differentiation between populations of W. ganpi. And the effects of inbreeding were observed, as well as asexual reproduction in some populations. Therefore, to conserve W. ganpi, all the surveyed populations need to be designated for on-site conservation and monitored continually. A research on the spatial genetic structure needs to be conducted to obtain information on sample extraction for off-site conservation. This structure would be able to minimize the wasting of samples that could be obtained from limited genetic resources and would enable further focused and efficient management.

Bhutanese forests have been well preserved and can sequester the atmospheric carbon (C). In spite of its importance, understanding Bhutanese forest C dynamics was very limited due to the lack of available data. However, forest C model can simulate forest C dynamics with comparatively limited data and references. In this study, we aimed to simulate Bhutanese forest C dynamics at 6 plots with the Forest Biomass and Dead organic matter Carbon (FBDC) model, which can simulate forest C cycles with small amount of input data. The total forest C stock (Mg C ha-1) ranged from 118.35 to 200.04 with an average of 168.41. The C stocks (Mg C ha-1) in biomass, litter, dead wood, and mineral soil were 3.40-88.13, 4.24-24.95, 1.99-20.31, 91.45-97.90, respectively. On average, the biomass, litter, dead wood, and mineral soil accounted for 36.0, 5.5, 2.5, and 56.0% of the total C stocks, respectively. Although our modeling approach was applied at a small pilot scale, it exhibited a potential to report Bhutanese forest C inventory with reliable methodology. In order to report the national forest C inventory, field work for major tree species and forest types in Bhutan are required.

Pig producers have been shown keen interest of the number of spermatozoa in a semen dose since pig artificial insemination introduce. However, determining the minimal number of spermatozoa need per AI without detrimental effect on overall reproductive performances is not an easy question to answer. To increase the efficiency of semen utilization in pig AI, optimum number of spermatozoa per dose needed to determine. The objective of this study was to determine the reproductive performance and factors that affect on-farm application of low-dose semen insemination in sows. Data were collected from Darby Genetics AI studs from 4th of June to 7th of July, 2012 (n=401). The numbers of parturition were 84, 234 and 83 in sows inseminated with doses of 1.5×109, 2.0×109 and 2.5×109 spermatozoa in 100ml extender, respectively. There were no significant differences on reproductive performances such as gestation pe-riod, total born, total born alive, stillbirth and mummy in sows inseminated with different semen doses. The average number of born alive was 10.5, 11.0 and 10.4 from sows inseminated with 1.5×109, 2.0×109 and 2.5×109 sperms, re- spectively. Also, number of spermatozoa per dose did not affect litter size (p>0.10). There were no significant differ-ences of maternal genetic line difference on gestation period, total number born, number born alive, born dead and mummy. The estimated correlation coefficients of the different semen doses with total number born, number born alive, born dead and mummy were r=—0.00, —0.01, 0.02 and 0.02, respectively. Taken together, the result of this study suggested that when semen was appropriately inseminated after induced ovulation, insemination with low-dose (1.5∼2.0×109) semen dose not adversely affect sow’s fertility.

옥수수 교잡종 111종의 습해저항성과 생육특성을 규명하기 위하여 인공기상동에서 3엽기에 인공강우 조건(1일차 80 mm, 이후 50 mm, 온도 21±3oC) 에서 본 시험을 수행하였다. 조사항목은 생육특성으로서 지상부, 뿌리, 엽신의 건물중을 조사하였으며 식물체의 중심고, 간직경을 측정 하였다. 교잡종 중에서 62번이 간장이 가장 길었으며 96번이 가장 짧았다. 무게중심고는 96번이 가장 컸으며 88번이 가장 짧았다. 건물중은 59번이 가장 무거웠으며 25번이 가장 낮았다. 간직경은 91번이 가장 두꺼웠으며 24번이 가장 가늘었다. 엽신건물중은 42번이 가장 컸고 25번이 가장 낮았다. 뿌리 건물중은 16번이 가장 높았고 24번이 가장 낮았다. 엽신건물중은 85번이 가장 높았고 25번이 가장 낮았다. 각 항목별 상관을 구한결과 간직경, 초장, 뿌리건물중은 엽신건물중과 정상관을 나타냈고 간직경과 초장은 뿌리건물중과 정상관을 보였으나 초장과 무게중심고는 부의 상관을 보였다. 무게중심고와 간직경 또는 간직경은 뿌리건물중과 상관을 보이지 않았다.

포장조건에서 22종의 옥수수교잡종을 과습조건에서 도복관련형질들의 상호관련성을 검정하였는데 좌절중 (1.0 m, 1.5 m)과 좌절부위등을 평가하였고 주요한 도복 저항성 형질인 좌절중, 간직경, 뿌리건물중, 중심고등의 상호 관련성을 함께 평가하였다. 본시험은 포트시험에서 일차 스크린 한 것을 논에 경사지를 만들어 경사지별로 수분함량과 도복저항성을 비교하기 위하여 관수시기(과습조건)를 파종후 20일, 5엽기, 출웅기, 출사기로 구분하였고 관수량은 100 mm/일 씩 5일간 처리하였으며 조사는 수확기에 수행 하였다. 본시험의 결과 출사기에 1.0 m, 1.5 m 높이에서 좌절중과 중심고는 정의 상관을 보였으며 파종후 20일차에 관수처리구에서는1.0m, 1.5m 모두 좌절강도와 간직경이 정의 상관을 나타냈다. 관수처리 5엽기에서는 높이 1.0 m에서 좌절강도와 간직경간의 강한 정의 상관을 나타냈으며 도복관련 형질인 간직경, 뿌리건물중,지상부 중심고, 좌절중, 좌절고등이지만 관수처리시 이들을 가장쉽게 판별 할 수 있는 방법은 5엽기에 관수처리구가 가장 효율적으로 사료된다.