Kori Unit 1, the first commercial nuclear power plant (NPP) in Korea, was permanently shut down in 2017 and was scheduled for decommissioning. Various programs must be planned early in the decommissioning process to safely decommission NPPs. Radiological characterization is a key program in decommissioning and should be a high priority. Radiological characterization involves determining the decommissioning technology to be applied to a nuclear facility by identifying the radiation sources and radioactive contaminants present within the facility and assessing the extent and nature of the radioactive contaminants to be removed from the facility. This study introduces the regulatory requirements, procedures, and implementation methods for radiological characterization and proposes a methodology to link the results of radiological characterizations for each stage. To link radiological characteristics, this study proposes to conduct radiological characterization in the decommissioning phase to verify the results of radiological characterization in the transitional phase of decommissioning NPPs. This enables significantly reducing the scope and content of radiological characterization that must be performed in the decommissioning phase and maintaining the connection with the previous phase.
The Yeongsan River is a prominent inland waterway, alongside the Han River, Nakdong River, and Geum River in South Korea. Numerous bacterial strains were isolated from the Yeongsan River basin for a comprehensive investigation into indigenous prokaryotic species conducted between 2020 and 2023. These bacterial strains were identified using 16S rRNA gene sequencing, wherein 45 bacterial strains shared >98.7% sequence similarities with bacterial species not recorded in Korea thus far. Therefore, this study aimed to catalogue aforementioned unrecorded species and characterize them contingent upon their Gram nature, colony and cell morphologies, biochemical properties, and phylogenetic positions. These bacterial species were determined to be phylogenetically diverse. They were categorized into nine classes, 18 orders, and 25 families. These previously unrecorded species were classified into the following genera and classes: Chitinophaga (class Chitinophagia); Flavobacterium (class Flavobacteriia); Rhodopseudomonas, Gemmobacter, Paracoccus, Azospirillum, Sphingomonas, Novosphingobium, Sphingorhabdus, and Erythrobacter (class Alphaproteobacteria); Bordetella, Pararobbsia, Polynucleobacter, Rhodoferax, Aquabacterium, Malikia, Comamonas, Ideonella, Paucibacter, Undibacterium, Cupriavidus, and Thauera (class Betaproteobacteria); Pectobacterium, Arenimonas, Lysobacter, and Luteimonas (class Gammaproteobacteria); Luteolibacter (class Verrucomicrobiia); Mycolicibacterium, Angustibacter, Ornithinibacter, Janibacter, Schumannella, Aurantimicrobium, Luedemannella, Nocardioides, and Propionicimonas (class Actinomycetes); Geothrix (class Holophagae); and Lactococcus (class Bacilli).
국립원예특작과학원에서는 밝은 화색과 안정적인 화형의 생 육이 우수한 빨간색 스탠다드 장미 품종을 육성하기 위해 진한 적색 스탠다드 장미 품종 ‘엔드리스러브(Endless Love)’를 모 본으로, 꽃잎수가 많고 안정적으로 가시가 적은 밝은 노란색 ‘페니레인(Penny Lane)’ 품종을 부본으로 인공교배하였다. 37 개의 교배실생을 양성해 1, 2, 3차에 걸친 특성검정 및 현장실증 을 통해 꽃이 크고 화형이 안정적이며, 재배안정성 및 생산성, 절화특성이 우수한 ‘원교 D1-390’을 최종 선발하였다. 2023년 ‘루비레드(Ruby Red)’로 명명하여 국립종자원에 품종보호출원·등록되었다. ‘루비레드’ 품종은 밝은 적색(R53C)을 가졌으 며, 꽃잎수가 32.8매, 화폭과 화고는 각각 10.9, 5.9cm로 대조 품종보다 크다. 절화장은 평균 71.7cm, 절화수명은 약 16.7일, 수량은 연간 168대/m2로 대조품종인 ‘레드스퀘어(Red Square)’ 대비 절화장이 길고 절화수명도 2배 이상 길며, 수확량도 1.4배 우수하다. 2023년 국내 육성 장미 품종 서울식물원 관람객 대상 공동평가회에서 스탠다드 장미 중 우수한 평가를 받았으며, 현 장 실증 결과 농가별로 균일하고 우수한 수량과 절화품질을 보 였다. 절화용 장미 ‘루비레드’ 품종은 밝은 적색과 우수한 화형 을 가지는 품종으로 해외 대체 품종으로 국내에서 많이 재배될 것으로 기대된다.
Vitrification, one of the most promising solidification processes for various materials, has been applied to radioactive waste to improve its disposal stability and reduce its volume. Because the thermal decomposition of dry active waste (DAW) significantly reduces its volume, the volume reduction factor of DAW vitrification is high. The KHNP developed the optimal glass composition for the vitrification of DAW. Since vitrification offers a high-volume reduction ratio, it is expected that disposal costs could be greatly reduced by the use of such technology. The DG-2 glass composition was developed to vitrify DAW. During the maintenance of nuclear power plants, metals containing paper, clothes, and wood are generated. ZrO2 and HfO2 are generally considered to be network-formers in borosilicate-based glasses. In this study, a feasibility study of vitrification for DAW that contains metal particulates is conducted to understand the applicability of this process under various conditions. The physicochemical properties are characterized to assess the applicability of candidate glass compositions.
The genus Anaclasiger which is one of the myrmecophilous beetle (Clavigeritae) was described by Raffray in 1890 with the type species, A. sinuaticollis. Since then, only one species, A. zhudiae, had been added in this genus. The former species has known to distribute in Singapore (type locality), Taiwan (Raffray, 1914), Malaysia (Nomura & Idris, 2005), Thailand and Japan (Nomura et al., 2006), and the latter has been reported only in China (Yin et al., 2012). During specimens research of Korea National Arboretum, we were recognized one species, A. sinuaticollis, collected by pitfall trap in Mt. Geombong. Therefore, we are going to report this unrecorded genus and species for the first time from Korea. Both the information of the species including diagnosis, habitus and male genitalia, and that of the genus distribution on the map are going to be provided.
Climate change has led to increased insect pests and pest distribution changes. Traditionally, chemical control using synthetic pesticides has been the main method for pest management, but the emergence of pesticide-resistant pests has become a problem. There is a need to develop new pest control agents to overcome these issues. Entomopathogenic fungi used in pest management have minimal environmental side effects and possess a mechanism of action distinct from that of synthetic pesticides. However, there is a need for the development of technologies to maximize the insecticidal effects of fungi against pests, and expressing and releasing dsRNA within the fungi can preemptively knock out the activation of the insect’s defense system, thereby enhancing the insecticidal effect. Controlling insect defense genes and using entomopathogenic fungi as bio-carriers forms a new pest management strategy. This approach, described as a “microbial insecticide agents development strategy of cassette concept, ” can versatilely modify genes and microbes. It is expected to overcome the limitations of synthetic pesticides.
Since rice is the main food in Korea, there are no regulations on corn milling yet. Corn is known as one of the world's top three food crops along with wheat and rice, and it is known that 3.5 billion people worldwide use corn for food. In addition, corn mills are not developed or sold in Korea, but the use of corn mills is increasing significantly in many countries in Southeast Asia. In the Philippines, as Korea's rice mill import increases, Korea's KAMICO (Korea Agricultural Machinery Industry Cooperative) and domestic company A agreed to develop a corn mill jointly with PHilMech, an organization affiliated with the Philippine Ministry of Agriculture. However, research on corn milling was very insignificant, so the development was carried out based on the technology of Korea's rice mill. Rice milling is performed by peeling off the skin of rice and producing brown or white rice, so it is carried out by removing the skin and cutting the skin. On the other hand, in the corn mill, the skin of the corn is peeled, pulverized and selected to produce main products suitable for edible use. Therefore, in order to develop a corn mill, processes such as peeling, transfer, grinding, sorting, and by-product separation are required, and suitable parts must be developed. In addition, the performance must be gradually improved through experiments in which corn is repeatedly milled. The Philippines produces 7.98 million tons/year of corn, which is about 100 times that of Korea, and is mostly consumed as a staple food. This is about 10% of the total crop production in the Philippines. In addition, the main cultivation complexes of corn are the mountainous regions of Tarlac or Pangasinan, and the produced corn is 72.4% of the so-called yellow corn called Arabel and Sarangani, and the remaining 27.6% are known as white corn. In this study, it was intended to produce grains of 2.5 mm or less suitable for food for yellow corn and to develop a corn mill for 200 kg per hour. Detailed conditions for development are stipulated as more than 55% of the main product recovery rate, more than 31% of the by-product recovery rate, less than 5% of the raw material loss rate, and more than 80% of the embryo dislocation rate. In this study, to achieve this, the overall process of the corn mill was developed, and the optimal conditions for the corn mill were obtained through the development of parts and empirical tests to improve performance. In addition, it was intended to achieve the development goal by evaluating and analyzing the performance of each part so that it did not conflict.
가상의 공간에서 함께 즐기는 콘텐츠에 대해 관심이 늘어나고 있다. 더불어 가상공간에서 나만의 아바타도 꾸미고 게임 콘텐츠 역시 즐기고 있다. 이러한 가상의 공간을 메타버스라고 하며 대표적인 플랫폼으로는 제 페토와 로블록스가 있다. 메타버스 플랫폼은 플랫폼의 취지에 맞게 유저가 직접 제작하기 편리한 컨텐츠 제 작 도구를 지원한다. 그러나 일반 유저가 제작한 콘텐츠는 메타버스에서 활동하고 있는 다양한 유저의 관심 과 흥미를 지속적으로 유발하기에는 부족한 부분이 있어 꾸준한 흥행이 어렵다. 본 논문은 기존 게임 엔진을 활용해서 콘텐츠를 제작하는 콘텐츠 개발자로서 메타버스 플랫폼이 제공하는 제작 도구의 효용성을 검증하 고자 게임 엔진의 선택 기준을 참고하여 인터페이스, 개발 언어, 개발 공정의 기준으로 대표하는 플랫폼의 제작 도구를 비교하였다.
One of the important components of a nuclear fuel cycle facility is a hot cell. Hot cells are engineered robust structures and barriers, which are used to handle radioactive materials and to keep workers, public, and the environment safe from radioactive materials. To provide a confinement function for these hot cells, it is necessary to maintain the soundness of the physical structure, but also to maintain the negative pressure inside the hot cell using the operation of the heating, ventilation, and air conditioning (HVAC) systems. The negative pressure inside the hot cells allows air to enter from outside hot cells and limits the leakage of any contaminant or radioactive material within the hot cell to the outside. Thus, the HVAC system is one of the major components for maintaining this negative pressure in the hot cell. However, as the facility ages, all the components of the hot cell HVAC system are also subject to age-related deterioration, which can cause an unexpected failure of some parts. The abnormal operating condition from the failure results in the increase of facility downtime and the decrease in operating efficiency. Although some major parts are considered and constructed in redundancy and diversity aspects, an unexpected failure and abnormal operating condition could result in reduction of public acceptance and reliability to the facility. With the advent of the 4th Industrial Revolution, prognostics and health management (PHM) technology is advancing at a rapid pace. Korea Hydro & Nuclear Power, Siemens, and other companies have already developed technologies to constantly monitor the integrity of power plants and are applying the technology in the form of digital twins for efficiency and safety of their facility operation. The main point of PHM, based on this study, is to monitor changes and variations of soundness and safety of the operation and equipment to analyze current conditions and to ultimately predict the precursors of unexpected failures in advance. Through PHM, it would be possible to establish a maintenance plan before the failure occurs and to perform predictive maintenance rather than corrective maintenance after failures of any component. Therefore, it is of importance to select appropriate diagnostic techniques to monitor and to diagnose the condition of major components using the constant examination and investigation of the PHM technology. In this study, diagnostic techniques are investigated for monitoring of HVAC and discussed for application of PHM into nuclear fuel cycle facilities with hot cells.
The thermal treatment of radioactive waste attracts great attention. The thermal treatment offers lots of advantages, such as significant volume reduction, hazard reduction, increase of disposal safety, etc. There are various thermal technologies to waste. The developed technologies are calcination, incineration, melting, molten salt oxidation, plasma, pyrolysis, synroc, vitrification, etc. The off-gas treatment system is widely applied in the technologies to increase the safety and operation efficiency. The thermal treatment generates various by-product and pollutants during the process. The dust or fly ash are generated as a particulate from almost every radioactive waste. The treatment of PVC related components generates hydrogen chloride, which usually brings corrosion of facility. The treatment of rubber and spent resin generates sulfur oxide, SOx. The treatment of nitrile rubber generates nitrogen oxide, NOx. The incomplete combustion of radioactive waste usually generates carbon oxide, COx. The process temperature also affects the generation of off gas, such as NOx and/or COx. Various off gas treatment components are organized for the proper treatment of the previously mentioned materials. In this study systematical review on off gas treatment will be reported. Also, worldwide experiences and developed facility will be reported.