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.

Decommissioning waste is generated with various types and large quantities within a short period. Concrete, a significant building material for nuclear facilities, is one of the largest decommissioning wastes, which is mixed with aggregate, sand, and cement with water by the relevant mixing ratio. Recently, the proposed treatment method for volume reduction of radioactive concrete waste was proven up to scale-up testing using unit equipment, which involved sequentially thermomechanical and chemical treatment. According to studies, the aggregate as non-radioactive material is separated from cement components with contaminated radionuclides as less than clearance criteria, so the volume of radioactive concrete waste is decreased effectively. However, some supplementation points were presented to commercialize the process. Hence, the process requires efficiency as possible to minimize the interface parts, either by integration or rearranging the equipment. In this study, feasibility testing was performed using integrated heating and grinding equipment, to supplement the possible issue of generated powder and dust during the process. Previously, heat treatment and grinding devices were configured separately for pilot-scale testing. But some problems such as leakage and pipe blockage occurred during the transportation of generated fine powder, which caused difficulties in maintaining the equipment. For that reason, we studied to reduce the interface between the equipment by integrating and rearranging the equipment. To evaluate the thermal grinding performance, the fraction of coarse and concrete fines based on 1mm particle size was measured, and the amount of residual cement in each part was analyzed by wet analysis using 4M hydrochloric acid. The result was compared with previous studies and the thermomechanical equipment could be selected to enhance the process. Therefore, it is expected that the equipment for commercialization could be optimized and composed the process compactly by this study.

The radiolytic decomposition of oxalic acid was investigated using gamma irradiation for decontamination of nuclear power systems. The study used high-purity analytical grade chemicals, with initial concentrations of oxalic acid prepared at 1, 2, 5, and 10 mM, and the initial pH was adjusted to 2-3 at each test condition. Gamma irradiation was performed using a high-level Co-60 source, and absorbed doses were 5, 10, 20, 30, and 50 kGy. The results showed that the efficiency of gamma irradiation decreased with longer gamma exposure time, and the G-value increased with the initial concentration of oxalic acid. Interestingly, the G-value decreased with accumulated radiation dose, but the removal increased. The dose constant ranged from 0.1695 to 0.0536 kGy-1 at different initial concentrations, and the G-value was inversely proportional to the dose constant. The study concluded that oxalic acid was successfully degraded by gamma irradiation, and 92% removal was obtained at the initial concentration of 10 mM. The mineralization of oxalic acid at higher concentrations was more difficult due to the great number of generated intermediates.

With the aging of nuclear power plants (NPPs) in 37 countries around the world, 207 out of 437 NPPs have been permanently shutdown as of August 2022 according to the IAEA. In Korea, the decommissioning of NPPs is emerging as a challenge due to the permanent shutdown of Kori Unit 1 and Wolsong Unit 1. However, there are no cases of decommissioning activities for Heavy Water Reactor (HWR) such as Wolsong Unit 1 although most of the decommissioning technologies for Light Water Reactor (LWR) such as Kori Unit 1 have been developed and there are cases of overseas decommissioning activities. This study shows the development of a decommissioning waste amount/cost/process linkage program for decommissioning Pressurized Heavy Water Reactor (PHWR), i.e. CANDU NPPs. The proposed program is an integrated management program that can derive optimal processes from an economic and safety perspective when decommissioning PHWR based on 3D modeling of the structures and digital mock-up system that links the characteristic data of PHWR, equipment and construction methods. This program can be used to simulate the nuclear decommissioning activities in a virtual space in three dimensions, and to evaluate the decommissioning operation characteristics, waste amount, cost, and exposure dose to worker. In order to verify the results, our methods for calculating optimal decommissioning quantity, which are closely related to radiological impact on workers and cost reduction during decommissioning, were compared with the methods of the foreign specialized institution (NAGRA). The optimal decommissioning quantity can be calculated by classifying the radioactivity level through MCNP modeling of waste, investigating domestic disposal containers, and selecting cutting sizes, so that costs can be reduced according to the final disposal waste reduction. As the target waste to be decommissioning for comparative study with NAGRA, the calandria in PHWR was modeled using MCNP. For packaging waste container, NAGRA selected three (P2A, P3, MOSAIK), and we selected two (P2A, P3) and compared them. It is intended to develop an integrated management program to derive the optimal process for decommissioning PHWR by linking the optimal decommissioning quantity calculation methodology with the detailed studies on exposure dose to worker, decommissioning order, difficulty of work, and cost evaluation. As a result, it is considered that it can be used not only for PHWR but also for other types of NPPs decommissioning in the future to derive optimal results such as worker safety and cost reduction.

This study investigated the effects of drying methods and drying time on the changes in anthocyanin content in colored barley. Colored barley cultivar Boanchalbori was harvested at a time when the anthocyanin content was the most and dried in afield. The harvested barley was then treated by two methods, sun drying and shade drying, for 4, 8, 24, and 32 h. The moisture content of the sun-dried barley decreased slightly faster than shade-dried samples, but the difference was not statistically significant. Chemical analysis indicated that the samples dried under shaded conditions had slightly higher crude fiber and lower nitrogen free extract, but the difference was not statistically significant. There was no difference in the total digestible nutrients between the two methods. In the case of sun-dried barley, the anthocyanin content decreased compared to the control and shade-dried samples after drying for 4 h (p < 0.05), was maintained at a constant level at 24 h, and then decreased at 32 h. In case of shade-dried barley, the anthocyanin content decreased gradually with the drying time, and a significant decrease was found at 24 h of drying (p<0.05) as compared to the control. The shade-dried method was more successful in reducing anthocyanin loss than the sun-dried method (p<0.05). There was a slight decrease in 1,1-Diphenyl-2-Picrylhydrazyl radical scavenging with drying time in the shade-dried method, and a significant decrease after 4 h with the sun-dried method. These results showed that covering with a two-layer awning was advantageous to dry colored barley in the field conditions.

This study was conducted to observe the fermentative quality and anthocyanin content in whole crop colored barley silage during storage periods and anthocyanin stability in in vitro ruminal fluid. Silages of colored barley cultivar “Boanchalbori” and normal barley cultivar “Yuyeonbori” were stored during 0, 2, 4, 6, and 12 months. The in vitro ruminal fluid was fermented for 0, 6, 12, 24, and 48 hrs. For the feed value, crude protein of colored barley silage was slightly increased in the silage compared to that of normal barley silage, and being increased up to 2 months after ensiling and thereafter maintained at the similar level. Neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of both the barley significantly increased by prolonged storage of 2 months (p<0.05), but they were maintained at the constant level after 2 months of storing silage. Whereas TDN (total digestible nutrients) contents of them were decreased by the prolonged storage of 2 months (p<0.05), then maintained at the constant levels. The fermentative quality and pH values in both the barley silages were slightly decreased during the storage time. Lactic acid and acetic acid contents were increased during prolonged storage period, but not significantly different among treatments. Butyric acid was not detected. In the colored barley silage, pH value showed slightly lower compared to that of the normal barley silage but not significant, and lactic acid content was significantly higher than the normal barley silage (p<0.05). The total anthocyanin content in the whole crop colored barley silage decreased to 42% after 2 months of ensilage, however maintained at the constant level until 12 months of ensilage. In the case of anthocyanin stability on in vitro ruminal fluid digestion, the pH value of the ruminal fluid was slightly lower at 6, 12, 24, 48h incubation time and the content of anthocyanin was at similar levels. These results indicated that the colored barley showed higher fermentation quality, and total anthocyanin content was maintained stable at 42% level of the first value in storing silage. As the anthocyanin had higher stability in the ruminal fluid, the colored barley has a potential as functional feeds for Ruminants.

We tested the identification ability of DNA barcodes comparing with morphological data using the Korean butterflies. The 921 samples (4.6 samples per species) for 202 resident Korean species except migratory species were used. The obtained samples were morphologically identified based on wing patterns. In a result, genetic divergence to the nearest-neighbouring taxon varied from 0 to 28.2%, with an average of 13.4 per cent. The neighbour joining (NJ) tree profile showed that sequence data for 185 of the 202 species formed distinct barcode clusters. Thus, our results indicated that 91.6 percent of the species were possible to allow the reliable identification using DNA barcoding. The rest 17 species (8.4%) consist of following four cases: clustering separated from each species by less than 1% branch length (two species pairs), paraphyletic clustering (two species pairs and one triple species pair), polyphyletic clustering with sharing barcodes (three species pairs), and clustering separated from existing species by the deep branch divergence (four clusters). However, it was not easy to interpret these ambiguous cases only using our current taxonomic evidences. Therefore, we are performing integrative taxonomy on these cases using other additional evidences such as examination on male genitalia and analysis of other gene regions.

독도의 식물에 대한 학술 연구는 1947년 이후부터 현재까지 꾸준히 이루어지고 있으며 독도의 자생하는 식물의 목록화를 통해 식물의 변화상을 관찰하고 있다. 최근 10년 전까지는 단순한 식물상 조사가 대부분이었으나, 2010년 이후부터는 분자수준의 연구와 함께 병행하여 독도 식물에 대한 연구방향이 다양해졌다. 이토록 독도 식물 연구에 많은 학자들 과 다양한 접근방법을 시도함에도 불구하고, 연구 대상종에 대한 학명과 국명의 사용이 학자들마다 매우 달랐다. 이에 본 연구는 2002년부터 2017년까지 독도 식물상 관련 논문 및 간행물 등을 검토하여 독도 식물의 학명과 국명의 사용과 그에 대한 변천과정에 대해서 연구하고 학술적으로 학명과 국명에 대한 정명을 제시하고자 한다. 학명의 변화가 있는 종들은 억새(Miscanthus sinensis Andress.), 술패랭이꽃(Dianthus longicalyx Miq.), 갯장대(Arabis stelleri DC.), 갯괴불주머니(Corydalis platycarpa (Maxim.) Makino), 바랭이(Digitaria sanguinalis (L.) Scop.), 갯제비쑥(Artemisia japonica subsp. littoricol (Kitam.) Kitam), 6종이다. 이중 특히 억새는 변종과 품종이 많아 추가적인 연구가 필요할 것으로 판단된다. 국명의 변화가 있는 종은 도깨비쇠고비, 갯까치수염, 쇠무릅, 가는갯능쟁이 등 4종이 있다. 독도 식물 중 일본과 관련되어 있는 학명이 존재하는데 특히, 일본지명 또는 국내 일본식 지명이 들어있는 학명은 참소리쟁이(Rumex japonica) 등으로 10과 10속 8종 1아종 1변종 10분류군이 있다. 또한 일본학자에 의해 명명된 학명은 가는 명아주(Chenopodium album var. stenophyllum Makino) 등 9과 10속 9종 1아종 3변 종 13분류군이 있는 것으로 확인되었다. 본 연구의 결과는 ICBN(국제식물명명규약)에 따라 검토하고 이를 바탕으로 정명을 제시하였다.

In this study, the phylogenetic relationship of Korean Hydrangea was evaluated by using sequenced three chloroplast regions and ITS region, including the 7 taxa. The result of phylogenetic analysis indicated that Korean Hydrangea, 7 taxa formed the monophyletic group. This analysis also revealed that subsect. Macrophyllae of Korea was separated into two groups; H. serrata f. acuminate and H. macrophylla group. The H. serrata f. acuminta group was included with H. serrata f. buergeri and H. serrata f. fertilis. These three species form a monophyletic clade, with no significant differences between their nucleotide sequences. The H. serrata f. acuminta group showed a monophyletic group with H. serrata f. buergeri and H. serrata f. fertilis and there is significant differences between their nucleotide sequences. H. macrophylla group was an independent clade distinguished by H. serrate f. acuminate group. Subsect. Petalanthe, Heteromallae and Calyptranthae form a monophyletic group. H. petiolaris which is located in Subsect. Calyptranthae was separated into two subgroups; First subgroup: Jeju island (except for Mt. Halla) and Second subgroup: Ulleung island and Japan. Additional studies of two subgroups of H. petiolaris should be conducted a geographical study and add more samples.

본 연구는 경북 영천시 보현산(북위 36° 08-09’, 동경 128° 57-59’, 해발고도 1,124 m)에 자생하는 식물의 분포를 파악하 기 위해 수행되었다. 2012년 3월부터 2014년 7월까지 총 22회에 걸쳐 조사된 관속식물은 총 105과 327속 522종 11아종 48 종 8품 종 589분류군으로 정리되었다. 한국고유종으로는 13분류군, 환경부지정 법적관리 보호식물Ⅱ급이 2분류군, 적색목록식물 이 10분류군, 식물구계학적 특정식물이 5등급이 5분류군, 4등 급은 5분류군, 3등급은 16분류군, 2등급은 20분류군, 1등급은 37분류군, 귀화식물이 37분류군으로 나타났다. 용도별 구성은 식용 240분류군(40.7%), 약용 205분류군(34.8%), 관상용 62분 류군(10.5%), 목초용 213분류군(36.2%), 목재용 15분류군(2.5%), 섬유용 8분류군(1.3%), 공업용 3분류군(0.5%)으로 나타났다.

Nitrogen (N) fertilization is essential for alleviating nutrient deficiencies of the world’s population by increasing rice production, one of the most important food crops of our time. Here we established an in vivo hydroponics rice seedling culture system to investigate the physio-biochemical and molecular responses of various rice genotypes to low nitrogen application. Yoshida’s nutrient solution (YS) was used to grow rice seedlings, and at three-week-old the seedlings manifested highly stable and reproducible symptoms, such as reduced shoot growth and length. Out of 12 genetically selected or tested genotypes, almost all (11 genotypes) showed varied degrees of growth reduction response to applied nitrogen (4 and 40 ppm N for treatment and control, respectively), but SR19663-B-B-34-3-3-3-1 showed similar growth as the control though its leaf width was smaller than the control. The leaves of a 11 representative low nitrogen-responsive genotype as BG90-2 were sampled for revealing the protein profiles between low and normal (control) nitrogen application by using two-dimensional gel electrophoresis (2-DGE) followed by staining of separated proteins with silver. Fifty differentially expressed silver stained protein spots were excised from 2-D gels and 41 proteins identified using high-throughput mass spectrometry (MS) using matrix-assisted laser desorption/ionization-time of flight-MS and nano electrospray ionization liquid chromatography tandem MS. These proteins could be assigned as major (energy metabolism, photosynthesis and oxidative stress) and minor functional categories, revealing many novel low N-responsive proteins, including those having energy/photosynthesis, and defense/stress, and iron homeostasis-related functions.