The chemical composition of 86 species of native plants in Korea, including plants to be afforestation, was analyzed. The chemical composition of the species analyzed was different. The species with the highest extractable content was Viburnum dilatatum (3.91%), and the species with the lowest extractable content was Ligustrum lucidum (0.11%). The lignin content ranged from 12 to 39%, with an average of 25%. The species with the highest lignin content was Chaenomeles lagenaria (39.37%). Hemicellulose content ranged from 18 to 52%, with the highest species being Thuja occidentalis (51.22%) and Eucommia ulmoides (48.84%). Cellulose content ranged from 25 to 58%, and the species with the highest content were Prunus serrulata (57.67%), Diospyros kaki (57.14%), Aesculus turbinata (53.29%), Albizia julibrissin (53.02%), and Zelkova serrata (52.29%). The chemical composition was different for each use taxon of 86 plant species. The lignin content was the highest in the fruit group and the lowest in the group other than recommended species for afforestation. Cellulose content was highest in non-reforestation-recommended tree species and lowest in fruit trees. In classification according to tree height, lignin content was higher in shrubs than in tall trees, and cellulose content was highest in tall trees. Between deciduous and evergreen trees, the lignin content was high in deciduous trees (26.46%), and the cellulose content was also high in deciduous trees (44.01%). As a result of analyzing the correlation between each compound, there was a difference. There tended to be a positive correlation between extractives and lignin content. There was a negative correlation between extractives and holocellulose content, hemicellulose and cellulose. The higher extract content affected the cellulose content much more than hemicellulose. Also, the higher the lignin content, the lower the cellulose content. The species with low lignin content and high cellulose content were Diospyros kaki and Prunus serrulata var. spontanea. This result is expected to be primary data for bioenergy, pulp industry and bioindustry.

The initial development plans for the six reactor designs, soon after the release of Generation IV International Forum (GIF) TRM in 2002, were characterized by high ambition [1]. Specifically, the sodium-cooled fast reactor (SFR) and very-high temperature reactor (VHTR) gained significant attention and were expected to reach the validation stage by the 2020s, with commercial viability projected for the 2030s. However, these projections have been unrealized because of various factors. The development of reactor designs by the GIF was supposed to be influenced by events such as the 2008 global financial crisis, 2011 Fukushima accident [2, 3], discovery of extensive shale oil reserves in the United States, and overly ambitious technological targets. Consequently, the momentum for VHTR development reduced significantly. In this context, the aims of this study were to compare and analyze the development progress of the six Gen IV reactor designs over the past 20 years, based on the GIF roadmaps published in 2002 and 2014. The primary focus was to examine the prospects for the reactor designs in relation to spent nuclear fuel burning in conjunction with small modular reactor (SMR), including molten salt reactor (MSR), which is expected to have spent nuclear fuel management potential.

경상남도농업기술원 화훼연구소에서 2021년 화색이 연황 색이며 화심이 녹색인 미니 절화용 거베라 품종 ‘크림쿠키’ (Cream Cookie)를 육성하였다. ‘크림쿠키’ 품종은 2014년 황색 미니 ‘Sun City’를 모본으로, 백색 미니 ‘Blandy’를 부 본으로 인공교배를 실시하여 육성된 품종이다. 2021년까지 생육 및 개화 특성검정과 기호도 조사를 실시하였으며 ‘크림 쿠키’의 생육 및 개화특성을 대조품종인 ‘Sun City’와 비교하 였다. ‘크림쿠키’는 연황색(RHS 4C) 꽃잎과 녹색 화심을 가진 반겹꽃 거베라 품종이다. 화폭이 7.1cm인 작은 꽃이며, 화경 장은 58.9cm였다. 화경 직경은 상부 0.4cm, 하부 0.7cm 였 다. 외부설상화의 길이는 2.8cm이며 폭은 0.8cm였다. 개화 소요일수는 65.7일로 ‘Sun City’에 비하여 18.8일 빨랐으며, 첫 개화시 엽수는 22.4매였다. 연간 주당 절화수량은 102.3 본으로 ‘Sun City’의 82.0본에 비하여 20.3본이 많았다. 절 화수명은 17.8일로 ‘Sun City’보다 4.1일 더 길었다. ‘크림쿠 키’는 화폭이 7.1cm의 미니 품종으로 연간 주당 100본 이상 절화 생산이 가능하다. 또한 수확 후 꽃 캡 씌우기, 꽃목 보강 등 추가적인 작업을 생략할 수 있어 생산비 절감이 가능하므 로 농가보급 확대가 기대된다.

Nasopharyngeal stenosis is defined as a morphological transition of narrowing at the nasopharyngeal region. A 2-yearold, castrated male, Korean short hair cat was referred to the animal medical center, Gyeongsang National University. According to clinical signs, diagnostic imaging, and physical examination, nasopharyngeal stenosis was diagnosed. The staphylectomy was performed using a CO2 laser, and there were not any post-operative complications. The patient was discharged in two days. This report describes the case of nasopharyngeal stenosis in cat and represents that laser ablation could be a good option for surgical management of the nasopharyngeal region with a low complication rate.

Foot-and-mouth disease (FMD), which affects cloven-hoofed animals, is economically important because of its highly contagious nature. FMD virus (FMDV), the causative agent of FMD, involves seven serotypes (O, A, Asia1, C, and SAT 1-3). Serotype Asia1 is unique to the Asian territory and is subdivided into nine genetic groups (G-I-IX) based on nucleotide variations in the VP1 sequence. Asia1 Shamir, the most representative Asia1 vaccine, is not highly protective against the Asia1/MOG/05 (G-V) lineage found in North Korea in 2007. Therefore, we investigated whether a chimeric virus strain (Asia1/MOG/Shamir), in which the VP4, VP2, and VP3 sequences of Asia1/MOG/05 were combined with the VP1 sequence of Asia1 Shamir, can simultaneously protect against both viruses. We determined the optimal viral growth conditions for the commercial utilization of this chimeric virus strain. Of the three types of cell culture media, the Cellvento medium resulted in the highest amount of antigen in the samples. The chimeric strain was proliferated in a small bioreactor to produce a test vaccine, and its immunogenicity was evaluated in pigs. The virus neutralization (VN) titer against the Asia1 Shamir virus was > 1/100 after the second immunization with the chimeric vaccine in pigs. In addition, a single dose of the test vaccine resulted in a VN titer of > 1/100 against the Asia1/MOG/05 strain. Taken together, our chimeric vaccine strain provided sufficient protection against the Asia1/MOG/05 and Asia1 Shamir viruses, suggesting its potential as a novel vaccine for both these strains.

The nuclear fuel that melted during the Fukushima nuclear accident in 2011 is still being cooled by water. In this process, contaminated water containing radioactive substances such as cesium and strontium is generated. The total amount of radioactive pollutants released by the natural environment due to the nuclear accident in Fukushima in 2011 is estimated to be 900 PBq, of which 10 to 37 PBq for cesium. Radioactive cesium (137Cs) is a potassium analog that exists in the water in the form of cations with similar daytime behavior and a small hydration radius and is recognized as a radioactive nuclide that has the greatest impact on the environment due to its long half-life (about 30 years), high solubility and diffusion coefficient, and gamma-ray emission. In this study, alginate beads were designed using Prussian blue, known as a material that selectively adsorbs cesium for removal and detection of cesium. To confirm the adsorption performance of the produced Prussian blue, immersion experiments were conducted using Cs standard solution, and MCNP simulations were performed by modeling 1L reservoir to conduct experiments using radioactive Cs in the future. An adsorption experiment was conducted with water containing standard cesium solution using alginate beads impregnated with Prussian blue. The adsorption experiment tested how much cesium of the same concentration was adsorbed over time. As a result, it was found that Prussian blue beads removed about 80% of cesium within 10-15 minutes. In addition, MCNP simulation was performed using a 1 L reservoir and a 3inch NaI detector to optimize the amount of Prussian blue. The results of comparing the efficiency according to the Prussian volume was shown. It showed that our designed system holds great promise for the cleanup and detection of radioactive cesium contaminated seawater around nuclear plants and/or after nuclear accidents. Thus, this work is expected to provide insights into the fundamental MCNP simulation based optimization of Prussian blue for cesium removal and this work based MCNP simulation will pave the way for various practical applications.

When occurring at a nuclear power plant (NPP) by accidents, accurate prediction and identification of the process of radioactive material dispersing into atmosphere is important to protect public and environment. Atmosphere dispersion of radioactive materials is significantly influenced by wind direction and wind speed. The government and nuclear operator continuously monitor wind data at nuclear sites through meteorological tower to prepare for such accidents involving the release of radioactive materials. The purpose of this study is to construct wind rose diagrams at 5 NPP sites (Kori, Saewool, Wolsong, Hanbit, Hanul). Wind roses serve as invaluable tool for identifying wind patterns in each region and visualizing wind directions. This can be utilized to predict the dispersion pathway and extent range of radioactive materials carried by the wind. This program will take on the role of establishing appropriate evacuation routes or shelter locations for residents when reliable wind data is not immediately available during an NPP accident. The wind data used in the study was collected from a meteorological tower located at the NPP site, and measurements were taken at 1-hour intervals for each operation over a period of ten years. The collected data underwent preprocessing, followed by the development of Python code to render the wind rose diagrams in an interpretable format. The future direction of this study will be focused on enhancing this program by integrating geographical mapping capabilities. With these advancements, it will become feasible to superimpose shelter positions on a map in accordance with prevailing wind directions. These improvements will contribute to the development of additional protective measures for residents and the proposal of alternative shelter options in response to potential radioactive material releases.

The domestic Pressurized Heavy Water Reactor (PWHR) nuclear power plant, Wolsong Unit 1, was permanently shut down on December 24, 2019. However, research on decommissioning has mainly focused on Pressurized Water Reactors (PWRs), with a notable absence of both domestic and international experience in the decommissioning of PHWRs. If proper business management such as radiation safety and waste is not performed, it can lead to increased business risks and costs in decommissioning. Therefore, the assessment of waste volume and cost, which provide fundamental data for the nuclear decommissioning process, is a crucial technical requirement before initiating the actual decommissioning of Wolsong Unit 1. Decommissioning radiation-contaminated structures and facilities presents significant challenges due to high radiation levels, making it difficult for workers to access these areas. Therefore, technology development should precede decommissioning process assessments and safety evaluations, facilitating the derivation of optimal decommissioning procedures and ensuring worker safety while enhancing the efficiency of decommissioning operations. In this study, we have developed a program to estimate decommissioning waste amounts for PHWRs, building upon prior research on PWR decommissioning projects while accounting for the specific design characteristics of PHWRs. To evaluate the amount of radioactive waste generated during decommissioning, we considered the characteristics of radioactive waste, disposal methods, packaging container specifications, and the criteria for the transfer of radioactive waste to disposal operators. Based on the derived algorithm, we conducted a detailed design and implemented the program. The proposed program is based on 3D modeling of the decommissioning components and the calculation of the Work Difficulty Factor (WDF), which is used to determine the time weighting factors for each task. Program users can select the cutting and packaging conditions for decommissioning components, estimate waste amount based on the chosen decommissioning method, and calculate costs using time weighting factors. It can be applied not only to PHWRs, but also to PWRs and non-nuclear fields, providing a flexible tool for optimizing decommissioning process.

Chelate resin is a resin that has an exchange group which can form chelates with various metal ions. It shows higher selectivity for metal ions than ion exchange resin and can selectively remove characteristic metal ions. In an aqueous solution containing metal ions, chelate resin can adsorb specific metal ions, and the separated chelate resin can desorb the adsorbed metal ions by changing temperature or pH, so chelate resin has the advantage of being reusable. Chelate resin has been used industrially as an adsorbent to adsorb and separate heavy metal ions in wastewater, and is also used for the purpose of recovering precious or rare metals contained in industrial wastewater or industrial waste. Against this background, there is a need to develop chelate resins with higher adsorption capacity. Acrylic fiber is defined as a man-made fiber made from a linear synthetic polymer with fiberforming ability consisting of more than 85% acrylonitrile. It is a man-made fiber that is often used as a substitute for wool because it has good thermal insulation properties like wool and is warm and soft to the touch. It is a fiber rich in cyano groups due to its high content of acrylonitrile, and has the advantage of being able to be used as a variety of functional fibers through modification of cyano groups. In this study, the amination reaction of acrylic fiber was performed using diethylenetriamine, and the adsorption characteristics for metal ions were evaluated according to the reaction conversion rate. In order to improve the amination efficiency, 400 kGy was irradiated using a 2.5 MeV electron beam accelerator, and through this, the crosslinking rate of acrylic fiber was able to be improved up to 80%. Water and ethanol were used as cosolvents for the amination reaction in a ratio of 60/40 vol/vol, respectively, and a reaction yield of 178% was obtained after 120 minutes of reaction. Using the chelate resin prepared in this way, the adsorption performance for metal ions was evaluated through Atomic Absorption Spectrometry analysis.

Radioactive contamination distribution in nuclear facilities is typically measured and analyzed using radiation sensors. Since generally used detection sensors have relatively high efficiency, it is difficult to apply them to a high radiation field. Therefore, shielding/collimators and small size detectors are typically used. Nevertheless, problems of pulse accumulation and dead time still remain. This can cause measurement errors and distort the energy spectrum. In this study, this problem was confirmed through experiments, and signal pile-up and dead time correction studies were performed. A detection system combining a GAGG sensor and SiPM with a size of 10 mm × 10 mm × 10 mm was used, and GAGG radiation characteristics were evaluated for each radiation dose (0.001~57 mSv/h). As a result, efficiency increased as the dose increased, but the energy spectrum tended to shift to the left. At a radiation dose intensity of 400 Ci (14.8 TBq), a collimator was additionally installed, but efficiency decreased and the spectrum was distorted. It was analyzed that signal loss occurred when more than 1 million particles were incident on the detector. In this high-radioactivity area, quantitative analysis is likely to be difficult due to spectral distortion, and this needs to be supplemented through a correction algorithm. In recent research cases, the development of correction algorithms using MCNP and AI is being actively carried out around the world, and more than 98% of the signals have been corrected and the spectrum has been restored. Nevertheless, the artificial intelligence (AI) results were based on only 2-3 overlapping pulse data and did not consider the effect of noise, so they did not solve realistic problems. Additional research is needed. In the future, we plan to conduct signal correction research using ≈10×10 mm small size detectors (GAGG, CZT etc.). Also, the performance evaluation of the measurement/analysis system is intended to be performed in an environment similar to the high radiation field of an actual nuclear facility.

Activated carbon (AC) is used for filtering organic and radioactive particles, in liquid and ventilation systems, respectively. Spent ACs (SACs) are stored till decaying to clearance level before disposal, but some SACs are found to contain C-14, a radioactive isotopes 5,730 years halflife, at a concentration greater than clearance level concentration, 1 Bq/g. However, without waste acceptance criteria (WAC) regarding SACs, SACs are not delivered for disposal at current situation. Therefore, this paper aims to perform a preliminary disposal safety examination to provide fundamental data to establish WAC regarding SACs SACs are inorganic ash composed mostly of carbon (~88%) with few other elements (S, H, O, etc.). Some of these SACs produced from NPPs are found to contain C-14 at concentration up to very-low level waste (VLLW) criteria, and few up to low-level waste (LLW) criteria. As SACs are in form of bead or pellets, dispersion may become a concern, thus requiring conditioning to be indispersible, and considering VLL soils can be disposed by packaging into soft-bags, VLL SACs can also be disposed in the same way, provided SACs are dried to meet free water requirement. But, further analysis is required to evaluate radioactive inventory before disposal. Disposability of SACs is examined based on domestic WAC’s requirement on physical and chemical characteristics. Firstly, particulate regulation would be satisfied, as commonly used ACs in filters are in size greater than 0.3 mm, which is greater than regulated particle size of 0.2 mm and below. Secondly, chelating content regulation would be satisfied, as SACs do not contain chelating chemicals. Also, cellulose, which is known to produce chelating agent (ISA), would be degraded and removed as ACs are produced by pyrolysis at 1,000°C, while thermal degradation of cellulose occurs around 350~600°C. Thirdly, ignitability regulation would be satisfied because as per 40 CFR 261.21, ignitable material is defined with ignition point below 60°C, but SACs has ignition point above 350°C. Lastly, gas generation regulation would be satisfied, as SACs being inorganic, they would be targeted for biological degradation, which is one of the main mechanism of gas generation. Therefore, SACs would be suitable to be disposed at domestic repositories, provided they are securely packaged. Further analysis would be required before disposal to determine detailed radioactive inventories and chemical contents, which also would be used to produce fundamental data to establish WAC.

Domestic waste acceptance criteria (WAC) require flowable or homogeneous wastes, such as spent resin, concentrated waste, and sludge, etc., to be solidified regardless of radiation level, to provide structural integrity to prevent collapse of repository, and prevent leaching. Therefore, verylow level (VLL) spent resin (SR) would also require to be solidified. However, such disposal would be too conservative, considering IAEA standards do not require robust containment and shielding of VLL wastes. To prevent unnecessary cost and exposure to workers, current WAC advisable to be amended, thus this paper aims to provide modified regulation based on reviewed engineering background of solidification requirement. According to NRC report, SR is classified as wet-solid waste, which is defined as a solid waste produced from liquid system, thus containing free-liquid within the waste. NRC requires liquid wastes to be solidified regardless of radiation level to prevent free liquid from being disposed, which could cause rapid release of radionuclides. Furthermore, considering class A waste does not require structural integrity, unlike class B and C wastes, dewatering would be an enough measure for solidification. This is supported by the cases of Palo Verde and Diablo Canyon nuclear power plants, whose wet-solid wastes, such as concentrated wastes and sludge, are disposed by packaging into steel boxes after dewatering or incineration. Therefore, dewatering VLL spent resin and packaging them into structural secure packaging could satisfy solidification goal. Another goal of solidification is to provide structural support, which was considered to prevent collapse of soil covers in landfills or trenches. However, providing structural support via solidification agent (ex. Cement) would be unnecessary in domestic 2nd phase repository. As the domestic 2nd phase repository is cementitious structure, which is backfilled with cement upon closure, the repository itself already has enough structural integrity to prevent collapse. Goldsim simulation was run to evaluate radiation impact by VLL SR, with and without solidification, by modelling solidified wastes with simple leaching, and unsolidified wastes with instant release. Both simulations showed negligible impact on radiation exposure, meaning that solidifying VLL SR to delay leaching would be irrational. Therefore, dewatering VLL SR and packaging it into a secure drum (ex. Steel drum) could achieve solidification goals described in NRC reports and provide enough safety to be disposed into domestic repositories. In future, the studied backgrounds in this paper should be considered to modify current WAC to achieve efficient waste management.

It has been known that as oxide layer (ZrO2) forms on the nuclear fuel cladding during irradiation in nuclear power plants, the corrosion kinetics are influenced by various parameters such as chemical environments. One of those environments, crud deposition driven by coolant chemistry has an adverse effect on the formation of oxide (ZrO2) and leads to increase thickness of the layer. In this study, crud formation was performed through loop experiment equipment on the surface of intentionally-made oxide layer (ZrO2) on cladding tubes and then the composition and characteristics of cruds were examined for the investigation of nuclear power plant environment. As a result, various cruds in composition and microstructure were formed depending on the exquisite methods and conditions such as metal ion concentration.

As global warming and consumer’s preference for tropical/subtropical fruits increase, the number of orchards cultivating tropical/subtropical fruits in Korea is increasing. Accordingly, concerns about the introduction of exotic invasive pests that host tropical fruits. In this study, efficacy of ethyl formate(EF), as alternative to methyl bromide(MB), was evaluated. Commercial trial of EF was conducted in mango post-harvest storage conditions for controlling Scirtothrips dorsalis. Application of 10 g/m3 of EF for 4 hours at 10 ℃ showed proven efficacy on S. dorsalis without any phytotoxic damage on mango fruits in that condition.

The two-spotted spider mite, Tetranychus urticae Koch, is one of the most important agricultural pests. Therefore, we screened fifteen compounds from natural products for their spatial repellent and oviposition deterrent activities against T. urticae in the laboratory by using two-choice and no-choice tests. In the bridge two-choice test, nine compounds showed the spatial repellent effects on T. urticae at 20 mg dose, resulting in reduced numbers of eggs. Among the nine compounds, at 2 mg dose, two compounds were selected as having more spatial repellent activity than the others. The two compounds also showed spatial repellent and oviposition deterrent effects in the two-choice test from hosts. In the no-choice test from a host, the spatial repellent effects of the two compounds to T. urticae were significantly stronger than that of controls. These results suggest that the findings can be used as potential agents for the prevention and population control of T. urticae in the field.

The cotton aphid, Aphis gossypii glover (Hemiptera: Aphididae), is the world-wide agriculture pest and has the ability to become resistant to many pesticides. Hence, we conducted behavioral tests on apterous and alate aphids for series compounds from natural products by using a two-choice test, a no-choice test, a host choice test and electroantennography (EAG). As a result, we found 3 out of 30 compounds for apterous aphids and 2 out of 15 compounds for alate aphids, both of which showed powerful repellent effects on these aphids. In this study, we suggest that our findings could be useful and eco-friendly spatial repellents for controlling cotton aphid.