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.

During the operation of nuclear power plant (NPP), the concentrates and spent resin are generated. They show relatively high radioactivity compared to other radioactive waste, such as dry active waste, charcoals, and concrete wastes. The waste acceptance criteria (WAC) of disposal facility defines the structure and property of treated waste. The concentrates and spent resin should be solidified or packaged in high integrity container (HIC) to satisfy the WAC in Korea. The Kori NPP has stored history waste. The large concrete package with solidified concentrates and spent resin. The WAC requires identification of 18 properties for the radioactive waste. Since some of the properties are not clearly identified, the large concrete packages could not satisfy the WAC in this moment. The generation of the large concrete package (rectangular type and cylindrical type), pretreatment of the package, treatment of inner drum, process development for clearance waste, etc. will be discussed in this paper. In addition, the conceptual design of whole treatment process will be discussed.

KORAD (Korea Radioactive Waste Agency, http://www.korad.or.kr) has stored slightly contaminated ascon (asphalt coated concrete mixture) that was introduced to Gyeongju repository about a decade ago waiting for a final disposal. It is believed to be mainly contaminated by radioisotope 137Cs due to impurities introduced from the outside during the ascon manufacturing process. We studied characteristics of the radioactive waste to see whether this material would be proper enough to be disposed in Gyeongju LILW repository or be other ways to reduce the disposal volume including self-disposal before its final disposal otherwise. KORAD looked into the properness of characteristics of ascon in terms of WAC (Waste Acceptance Criteria) documented by KORAD that includes general chemical and physical properties of asphalt, density, size of grains, content of organic material and possibility of existence of chelate materials that qualitatively limited to be disposed by the criteria. And other associated characteristics such as gas generation and bio degradation were also investigated. Based on the data obtained from the study, we proposed various plausible solutions in associated with operational and disposal safety and economic view points. This study will be used for KORAD’s decision on how to control and safely dispose the spent ascon within a reasonable time period. And also those experiences may be applied for other LILW issues that require treatment or conditioning of radioactive wastes in the future.

Kori Unit 1 was permanently shut down in 2017 and is currently being prepared for decommissioning. Decommissioning waste generated during the decommissioning of a nuclear power plant has the characteristic of being generated in large quantities over a short period. Therefore, if proper management is not carried out, abnormal situations (i.e., unauthorized disposal, diversion, etc.) may occur. According to IAEA General Safety Report Part 6, radioactive waste shall be managed for all waste streams in decommissioning. This means ensuring that all waste streams are managed by the recorded inventory of all decommissioning waste and verifying that the recorded inventory is reasonable. The radioactive waste management has been managed in units such as mass and radioactivity. However, in the case of decommissioning waste, the amount is very large, so management by radioactivity is expected to have limitations. Therefore, in this study, a simple test was conducted to verify the decommissioning waste generated by a hypothetical scenario by mass. In this study, establish a scenario assuming various flows of decommissioning waste expected to be generated and calculate the expected inventory of decommissioning waste using Microsoft Excel. Specifically, using “Material Unaccounted For” (MUF), a material balance equation in IAEA Services Series 15, Nuclear Material Accounting Handbook, the error inventory was calculated as the difference between the physical inventory of decommissioning waste in the area and the ending inventory. We propose a simple test scenario to verify the flow of decommissioning waste by verifying that the error inventory reasonably matches the set allowable error. This study aims to verify the inventory of decommissioning waste using the material balance methodology used for nuclear material accounting. It is expected that the safety and reliability of the nuclear power plant decommissioning process can be secured by verifying that the total inventory of equipment before decommissioning and the inventory of remaining equipment and decommissioning waste after decommissioning are reasonably consistent.

The solid-state chemistry of uranium is essential to the nuclear fuel cycle. Uranyl nitrate is a key compound that is produced at various stages of the nuclear fuel cycle, both in front-end and backend cycles. It is typically formed by dissolving spent nuclear fuel in nitric acid or through a wet conversion process for the preparation of UF6. Additionally, uranium oxides are a primary consideration in the nuclear fuel cycle because they are the most commonly used nuclear fuel in commercial nuclear reactors. Therefore, it is crucial to understand the oxidation and thermal behavior of uranium oxides and uranyl nitrates. Under the ‘2023 Nuclear Global Researcher Training Program for the Back-end Nuclear Fuel Cycle,’ supported by KONICOF, several experiments were conducted at IMRAM (Institute of Multidisciplinary Research for Advanced Materials) at Tohoku University. First, the recovery ratio of uranium was analyzed during the synthesis of uranyl nitrate by dissolving the actual radioisotope, U3O8, in a nitric acid solution. Second, thermogravimetric-differential thermal analysis (TG-DTA) of uranyl nitrate (UO2(NO3)2) and hyper-stoichiometric uranium dioxide (UO2+X) was performed. The enthalpy change was discussed to confirm the mechanism of thermal decomposition of uranyl nitrate under heating conditions and to determine the chemical hydrate form of uranyl nitrate. In the case of UO2+X, the value of ‘x’ was determined through the calculation of weight change data, and the initial form was verified using the phase diagram for the U-O system. Finally, the formation of a few UO2+X compounds was observed with heat treatment of uranyl nitrate and uranium dioxide at different temperature intervals (450°C-600°C). As a result of these studies, a deeper understanding of the thermal and chemical behavior of uranium compounds was achieved. This knowledge is vital for improving the efficiency and safety of nuclear fuel cycle processes and contributes to advancements in nuclear science and technology.

This study evaluated a potential sterilization process that uses calcium hypochlorite (Ca(ClO)2) as a disinfectant and hydrogen peroxide (H2O2) as a neutralizing agent for monoculture processes of microalgae (Nannochloropsis oculata). The results showed that no contaminants (prokaryote) were present when the Ca(ClO)2 concentration was greater than 0.010%. The use of an equivalent amount of H2O2 completely neutralized Ca(ClO)2 and had an additional bactericidal effect because of the formation of singlet oxygen. No substantial difference was observed in the biomass accumulation and chlorophyll contents compared to those in cultures sterilized using conventional physical methods such as autoclaving. Therefore, chemical sterilization using Ca(ClO)2 and H2O2 has an excellent economic advantage, and we expect the proposed ecofriendly chemical sterilization method to become a critical culture technology for microalgae-related industrialization.

Fulvic acid, a humic substance with unique properties, has sparked interest due to its potential applications in the treatment of allergic diseases, Alzheimer's disease, and as a microplastic adsorbent. However, conventional extraction methods produce insufficient quantities for commercial use, which has prompted research to enhance fulvic acid production. In this study, we investigated the impact of Saccharomyces cerevisiae fermentation on the yield and spectral characteristics of fulvic acid extracted from white peat. Fulvic acid was extracted from both S. cerevisiae-treated and untreated white peats using acid precipitation. The yield of fulvic acid from the S. cerevisiae treated group reached its highest at 3.5 % after 72 hr of fermentation, which was significantly higher than the untreated group (1.1 %). Fourier Transform Infrared (FTIR) analysis revealed similarities in functional groups and characteristic absorption bands between the treated and untreated fulvic acid samples. These findings suggest that S. cerevisiae fermentation can increase the yield of fulvic acid extracted from white peat, providing a promising approach for enhancing the commercial viability of fulvic acid production.

In this study, Bacillus velesensis TJS119, isolated from freshwater, demonstrated growth inhibition against insect pathogenic fungi. The culture medium of the B. velezensis TJS119 strain underwent sequential fractionation with n-hexane, chloroform, ethyl acetate, n-butanol, and water. Notably, the n-butanol fraction exhibited significant antifungal activity against Metarhizium anisopliae and Beauveria bassiana. LC/MS analysis of antifungal peaks identified the production of various lipopeptides by B. velezensis TJS119, including two types of iturin A (C14, C15), four types of fengycin A (C14, C15, C16, C17), and two types of fengycin B (C16, C17). The antifungal efficacy of Iturin A and Fengycin against insect pathogenic fungi was further validated using the paper disc diffusion method. These findings underscore the potential of B. velezensis TJS119 as a promising candidate for future research and applications in the realm of agricultural biological controls against fungal diseases.

본 연구는 주변 환경의 차이에 따른 화분매개곤충의 유입 특성을 파악하기 위하여 국립수목원 내 진화속을걷 는정원과 부추속전문전시원에 식재된 울릉산마늘의 화분매개곤충을 조사하였다. 2023년 5월 22일부터 6월 2일 까지 꽃이 70% 이상 개화하였을 때 포충망을 활용하여 8일간 곤충을 채집하였고, 각 전시원 별 식생(피도), 기후 (온도·습도·조도)를 조사하였다. 조사 결과 진화속을걷는정원에서 피도 60% 온도 26.4℃, 습도 31.5%, 조도 40953.6lx, 화분매개곤충 20과 450개체, 부추속전문전시원은 피도 90%, 온도 25.6℃, 습도 31.6%, 조도 6387lx, 화분매개곤충 15과 196개체로 나타났다. 온도와 조도가 상대적으로 높은 진화속을걷는정원이 채집된 곤충의 다양성과 방문 빈도가 높았다. 시간대별 곤충의 방문 빈도를 비교해본 결과 온도와 조도는 개체수가 증가할 때 같이 증가하는 경향을 보였으며, 습도는 반대의 경향을 보였다.

멸강나방은 중국 내 개체군이 북쪽 지역으로 2차 이주를 할 때, 봄철 제트기류를 타고 국내로 유입되는 비래해 충이다. 집단으로 발생 시 벼, 옥수수, 수수 등 여러 작물에 큰 피해를 준다. 2020년과 2021년 북방접경 세 지역(백령 도, 연천, 고성)과 수원 지역에서 성페로몬트랩을 이용하여 멸강나방의 성충 발생 시기를 탐지하였다. 일반적으 로 수원지역은 4월 하순 혹은 5월 상순에 최초 유인되었으나 두 해 여러 지역에서 공통적으로 탐지되는 시기는 6월 초중순이었다. 미국 해양대기청(NOAA)에서 제공하는 역궤적 분석프로그램(HYSPLIT)을 이용하여 각 지 역에서 멸강나방이 포획된 날짜 별 지상 300, 500, 700, 1000 m의 36~72시간 역궤적 분석을 수행하였다. 이후 같은 시기에 중국 내 멸강나방이 분포할 가능성이 높은 지역(32~40 ºN)을 비래 근원지로 추정하였다. 2021년 수원과 백령도에서 공통적으로 산둥성(山东省)이 근원지로 추정되었다. 공통적으로 산둥성(山东省)과 장수성(江苏 省)이 주 비래지로 추정되었고, 추가적으로 백령도는 허베이성(河北省), 수원은 안후이성(安徽省), 허베이성(河 北省), 저장성(浙江省)도 가능성이 있는 지역으로 추정되었다.

We analyzed comparatively the ground beetle communities of 1993 and 2023, with 30 year interval, in broadleaf and coniferous stands of the Gwangneung forest, a biosphere reserve in South Korea. 2,906 individuals (53 species, 38 genera, and 15 families) were collected from broadleaf stands and 1,782 individuals (36 species, 32 genera, and 14 families) from coniferous stands in 1993. The dominant species was Synuchus cycloderus in both stands. In 2023, 1,682 individuals (110 species, 78 genera, 21 families) were collected from broadleaf stands and 990 individuals (92 species, 67 genera, 22 families) from coniferous stands. In 2023, the dominant species were Eucarabus (Parhomopterus) sternbergi sternbergi in broadleaf stands and Coptolabrus jankowskii jankowskii in coniferous stands. Species richness (R'), species evenness (E'), species diversity (H'), and dominance (DI) were all higher than in broadleaf (R'=15.472, E'=0.336, H'=1.601, and DI=0.371) and coniferous (R'=13.756, E'=0.369, H'=1.324, and DI=0.326) forests in 2023.

기후변화와 세계시장 개방에 따른 외래 및 돌발해충의 종류는 다양해지고 밀도는 지속적으로 증가하고 있지 만 발생 실태에 관한 자료는 미흡하다. 본 연구는 경남지역 돌발 및 남방계 해충의 발생과 피해조사를 위해 미국선 녀벌레, 썩덩나무노린재, 담배거세미나방 등 3종을 경남 18시·군에서 조사하였다. 미국선녀벌레는 약충기(6월), 성충기(9월) 조사를 진행하였고, 길이가 50cm 이상되는 가지의 밑동에서 위쪽으로 50cm 내 개체를 육안조사하 였다. 썩덩나무노린재는 콩 개화기(7월), 등숙기(9월) 조사를 진행하였고 지점당 집합페로몬 트랩 1개를 설치하 고 1주 후 채집된 마리 수를 조사하였다. 담배거세미나방은 성페로몬 트랩 1개를 설치한 뒤 1주 후 채집된 마리 수를 조사하였다. 미국선녀벌레는 의령, 함안, 함양 등에서 발생이 많았고, 전년대비 발생이 소폭 감소하였다. 썩덩나무노린재는 합천, 밀양, 함양 등에서 발생이 많았고, 담배거세미나방은 전시군에서 발생이 확인되었으 며, 특히 함양, 산청, 사천, 고성 등에서 밀도가 높았다.

최근 기후변화에 따라 아열대 작물 재배가 증가하면서 경남지역 망고 재배면적도 크게 증가하고 있다. 하지만 망고에 발생하는 병해충 발생 정보가 부족하여 2022년부터 현재까지 경남지역에 있는 망고농장을 조사하였으 며, 그 결과 병해 6종, 해충 8종 발생을 확인하였다. 특히 경남지역 망고 포장에서 꽃노랑총채벌레, 대만총채벌레, 볼록총채벌레 등의 발생을 확인하였고, 통영, 함안, 밀양 등에서 총채벌레류에 의한 피해가 발생하였다. 많은 농가에서 총채벌레류 방제를 위해 화학농약에 의존하고 있으나 총채벌레는 반복적인 약제 노출시 빠른 세대 진전으로 인해 저항성 발달이 쉽기때문에 방제에 어려움을 겪고 있다. 이러한 문제를 해결하고자 색상별 끈끈이 트랩의 총채벌레류 유인효과를 확인하였으며, 꽃노랑총채벌레는 노랑, 주황, 연두, 대만총채벌레는 빨강, 노랑, 파랑, 볼록총채벌레는 파랑, 노랑, 빨강 순으로 유인효과가 높은 것을 확인하였다.

Until now, in case of Palaearctic region, only one species, Nesendaeus monochrous in this genus was recorded from China. but the biology and life cycle are not clearly known, yet. This species collected from the bud of Glochidion chodoense in Korea for the first time and closely related to Heterochyromera imerodeus Kojima & Morimoto which was recorded only in Japan,. But Nesendaeus monochrous is easily distinguishable from H. imerodeus by the relatively longer elytra with bisinuately round apices. Heterochyromera imerodeus Kojima & Morimoto can be found from Eurya emarginata and Glochidion obovatum in Japan. So, this two species are closely related each other and need more taxonomic study about the generic synonymy or changing the generic position.

Necrophila (Calosilpha) brunnicollis brunnicollis (Kraatz, 1877) is a common necrophagous beetle in the Palaearctic region. The species is often encountered on the corpses of large vertebrates, such as human and pig, and is well recognized as a potentially group of beetles in forensic entomology. All of the developmental stages can be found in the corpse and under the soil near a corpse, which can be used to reconstruct the site, such as estimating PMI(Postmortem interval). However, its larval instar stages were never thoroughly described for identification. In this study, we redescribe the morphological characters of all larval stages of N. brunnicollis for quantitative and qualitative morphological information. In addition, we provide the images of larvae and an indentrifiaction key to larval instars.

The genus Silpha Linnaeus, 1758 in Silphinae includes 33 species worldwide. This group is flightless and known to feed on invertebrate carcasses from the ground surface. In South Korea, 3 species have been recorded, and S. koreana Cho& Kwon, 1999 is an endemic species, distributed only Mt. Taebaek and Mt. Mindung. Up to date the immature stages of the species has never been studied although the species has significant value as an endemic species. The present study is the very first one ever conducted describing the larval morphological characters of S. koreana along with images of larval stages. Furthermore, we report observations on developmental lengths for each stages of the species.

A survey of plant-parasitic nematodes (PPNs) was carried out in medicinal crop cultivated fields from July to August in 2023. Three-leaf ladybell, Adenophora triphylla var. japonica is a highly valued medicinal plant that is used to treat or prevent bronchitis, cough, cancer, and obesity in Korea. A. triphylla plants with small root-galls were observed in a field of Yeongju Agricultural Technology Center, which were identified as a root-knot nematode. Additional morphological and molecular analyses studies were performed and identified as Meloidogyne hapla, Northern root-knot nematode. Population densities of M. hapla ranged from 20~30 nematodes per 100 cm3 of soil. M. hapla was detected at lower densities in soil compared to other infected host crops, but there are concerns about damage to M. hapla since A. triphylla is cultivated for more than two years once planted. Our results indicate that A. triphylla roots damage by M. hapla were identifed, it is necessary to prepare control methods such as registration of applicable nematicides and crop rotation.

최근 이식에 강하고 도심 환경에서의 스트레스에 강한 저항성을 지니고 있으며 병해충이 많이 없는 것으로 알려진 대왕참나무가 가로수 및 조경수로 많이 식재되고 있다. 하지만 대왕참나무의 식재량이 증가하면서 일부 지역에서 해충 피해가 보고되고 있고 이들에 대한 관리 대책 마련이 시급해지고 있다. 따라서 본 연구는 대왕참나 무의 식재 환경에 따른 해충 발생 양상을 조사하기 위해 수행하였다. 2022년부터 2023년 동안 7~8월 중에 조사를 수행하였으며, 육안조사법과 고지 가위를 활용하여 줄기와 잎에서 해충의 종별 개체수를 조사하였다. 대왕참나 무의 식재 환경은 도로변과 공원으로 구분하였고, 서울, 성남, 춘천, 원주, 여수, 함안, 창원 지역을 대상으로 진행 하였다. 조사 결과 총 20과 34종 1,126개체가 관찰되었으며 그 중 가로수에서 15과 18종 699개체가 관찰되었고 공원 지역에서 17과 27종 427개체가 관찰되었다. 가로수에서 나비목과 노린재목 해충이 더 많았으며 공원에서는 딱정벌레목 해충이 더 많았다.