KHNP is conducting research to decommission Wolsong Unit 1 Calandria. Establishment of preparation and dismantlement processes, conceptual design of equipment and temporary radiation protection facilities, and waste management are being established. In particular, the ALARA plan is to be established by performing exposure dose evaluation for workers. This study aims to deal with the methodology of evaluating exposure dose based on the calandria dismantling process. The preparation process consists of bringing in and installing tooling and devices, and removing interference facilities to secure work space. The main source term for the preparation process is the calandria structure itself and crud of feeders. In the case of the dismantlement process, a structure with a shape that changes according to the process was modeled as a radiation source. It is intended to estimate the exposure dose by selecting the number of workers, time, and location required for each process in the radiation field evaluated according to the preparation and dismantlement process. In addition, it is also conducting an evaluation of the impact on dust generated by cutting operations and the human impact of C-14, H-3, which are specialized nuclides for heavy water reactors. KHNP is conducting an exposure dose evaluation based on a process based on the preparation and dismantlement process for decommissioning Calandria through computation code analysis. If additional worker protection measures are deemed necessary through dose evaluation according to this methodology, the process is improved to prepare for the dismantling of worker safety priorities.

Although the proportion of coal-fired power generation is decreasing, efficient operating technology is needed to continuously invest in facilities and reduce maintenance costs until it is abolished. Boilers, one of the main facilities of power plants, operate for a long time in harsh environments of high temperature and high pressure. In addition, damage due to deterioration is likely to occur depending on the fuel and tube material used. It is very important to judge soundness because damage caused by deterioration adversely affects facility operation. Previously, replication method was used to analyze the progress of deterioration. In the replication method, pre-treatment such as chemical treatment is performed on the boiler tube in the field, the area is reproduced by attaching a film, and the replicated film is determined by an expert in the laboratory with an expensive microscope. However, this method involves substantial costs and time requirements, as well as the possibility of human errors. To address these issues, we developed a mobile health assessment system in this research. Since it is detachable and takes images in real time, this system enables swift evaluations across a broad range and facilitates the assessment of preprocessing quality. In addition, it was intended to reduce existing human mistakes by developing a degradation classification algorithm using the merger cluster method.

KHNP is carrying out international technical cooperation and joint research projects to decommission Wolsong unit 1 reactor. Construction data of the reactor structures, experience data on the pressure tube replacement projects, and the operation history were reviewed, and the amount of dismantled waste was calculated and waste was classified through activation analysis. By reviewing COG (CANDU owners Group) technical cooperation and experience in refurbishment projects, KHNP’s unique Wolsong unit 1 reactor decommissioning process was established, and basic design of a number of decommissioning equipment was carried out. Based on this, a study is being conducted to estimate the worker dose of dismantling workers. In order to evaluate the dose of external exposure of dismantling workers, detailed preparation and dismantling processes and radiation field evaluation of activated structures are required. The preparation process can be divided into dismantlement of existing facilities that interfere with the reactor dismantling work and construction of various facilities for the dismantlement process. Through process details, the work time, manpower, and location required for each process will be calculated. Radiation field evaluation takes into account changes in the shape of structures by process and calculates millions of areas by process, so integrated scripts are developed and utilized to integrate input text data. If the radiation field evaluation confirms that the radiation risk of workers is high, mutual feedback will be exchanged so that the process can be improved, such as the installation of temporary shields. The results of this study will be used as basic data for the final decommissioning plan for Wolsong unit 1. By reasonably estimating the dose of workers through computer analysis, safety will be the top priority when decommissioning.

Prevention of radiation hazards to workers and the environment in the event of decommissioning nuclear power plants is a top priority. To this end, it is essential to continuously perform radiation characterization before and during decommissioning. In operating nuclear power plants, various detectors are used depending on the purpose of measurement. Portable detectors used in power plants have excellent portability, but there is a limit to the use of a single measuring device alone to quantify radioactive contamination, nuclide analysis, and ensure representation of measurement results. In foreign countries, gamma-ray visualization detectors are being actively used for operating and decommissioning nuclear power plants. KHNP is also conducting research on the development of gamma-ray visualization detectors for multipurpose field measurement at decommissioning nuclear power plants. It aims to develop detectors capable of visualizing radioactive contamination, analyzing nuclides, estimating radioactivity, and estimating dose rates. To this end, we are developing related software according to the development process by purchasing sensors from H3D, which account for more than 75% of the US gamma-ray visualization detector market. In addition, field tests are planned in the order of Wolsong Unit 1 and Kori Unit 1 with Research reactor in Gongneung-dong in accordance with the progress of development. The detector will be optimized by analyzing the test results according to various gamma radiation field environments. The development detector will be used for various measurement purposes for Kori unit 1 and Wolsong

Nonthermal atmospheric plasma has been studied for its many biomedical effects, such as tooth bleaching, wound healing, and coagulation. In this study, the effects of dentinal tubules occlusion were investigated using fluoride-carboxymethyl cellulose (F-CMC) gel, nano-sized hydroxyapatite (n-HA), and nonthermal atmospheric plasma. Human dentin specimens were divided to 5 groups (group C, HA, HAF, HAP, and HAFP). Group HA was treated with n-HA, group HAF was treated with n-HA after a F-CMC gel application, group HAP was treated with n-HA after a plasma treatment and group HAFP was treated with n-HA after a plasma and F-CMC gel treatment. The occlusion of dentinal tubules was investigated using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS), which shows Ca/P ratio. In the EDS results, a higher Ca/P ratio was shown in the groups including n-HA than in the control group. The specimens of group HAP and HAFP had a higher Ca/P ratio in retentivity. In the SEM results, there was not a significant difference in the amount of times applied. Therefore, this study suggests F-CMC gel and n-HA treatment using nonthermal atmospheric plasma will be a new treatment method for decreasing hypersensitivity.

Recently real-estate investment business is standing out as a new plan for creation of source of income. In this paper, we suggested appropriate real-estate investment strategy through the reconstruct case study of existing one-storied building. That is, we showed the efficient process of decision and propel to reconstruct and the key points for lease business and post management after building completion. Also, we analyzed the rate of return of commercial building investment in order to find its optimum dealing time. Therefore the results of this paper are expected to be a help to old ages and persons laying plans for a similar business.

Recently real-estate investment business is standing out as a new plan for creation of source of income. In this paper, we suggested appropriate real-estate investment strategy through the reconstruct case study of existing one-storied building. That is, we showed the efficient process of decision and propel to reconstruct and the key points for lease business and post management after building completion. Also, we analyzed the rate of return of commercial building investment in order to find its optimum dealing time. Therefore the results of this paper are expected to be a help to old ages and persons laying plans for a similar business.

진흥(振興)과 유신(維新)을 공시(供試)하여 이앙시기(移秧時期), 재식밀도(栽植密度), 질소시비(窒素施肥) 수준(水準)과 벼잎집무늬마름병(病) 발생(發生)과의 관계(關係)를 검토(檢討) 하였다. 잎집무늬마름병(病) 발생(發生)은 5월(月) 26일(日) 이앙구(移秧區)보다 5월(月) 16일(日) 이앙구(移秧區)에서, 당 100주(株) 재식구(栽植區)가 80주(株) 재식구(栽植區)보다 , 질소질배비구(室素質倍肥區)(진흥(振興) 220kg/ha, 유신(維新) 300kg/ha) 가 보비구(普肥區)에서보다 발병(發病)이 심(甚)하였다. 또한 생육기간중(生育期間中) 발병(發病)이 심(甚)했던 재배조건(栽培條件)에서 성숙기(成熟期)의 피해도(被害度)가 높았다

Background : Recently, many studies to seek for medicinal herb compounds from natural products have been attempted capable of being free from harmful side effects and reducing the economic burden. This study was conducted to investigate whether Morus alba L.(MAL) water extracts has a biological safety, and an inhibitory potential against the mutagenicity induced by cigarette smoke condensates(CSC). Methods and Results : MAL was extracted with 70% ethanol and the yield of the extract was 35.1%. The 70% ethanol MAL extract was fractionated sequentially by diethylether, chloroform, dichloromethane, and water, respectively. Crude MAL 70% ethanol extract itself and its solvent fractions did not show any mutagenic effect up to 1 mg/plate toward Salmonella typhimurium TA 98 with or without the microsomal S-9 mixture of liver metabolic activations. On the other hand, the crude MAL extract showed an inhibitory activity against the mutagenicity of CSC with S-9 mixture. Diethyl ether layer among five solvent fractions showed the highest inhibitory activity at the same dose. The inhibitory activity of diethyl ether layer was also increased dose-dependently and the inhibitory rate was about 97.1% at the concentration of 1 mg/plate. Conclusion : In this study, we concluded that all of the crude MAL 70% ethanol extract and its solvent layers are potentially safe for mutagenicity and the diethyl ether layer among the crude MAL 70% ethanol extract has an inhibitory effect against the mutagenicity of CSC.

Background : Dioscorea quinqueloba(DQ) is a medicinal herb that is used as an alternative therapy for cardiovascular disease and various medical conditions. The objective of this study was to characterize the antioxidant activities of DQ. Methods and Results : The samples were extracted with Distilled water and analyzed for total flavonoid contents, polyphenol contents, DPPH radical scavenging activity, and ABTS radical scavenging activity. H9c2 cardiomyoblast cells were subjected to H2O2, to study the protective effect of DQ on cell viability, and ROS production. The total amounts of polyphenols and flavonoids, which indicate the antioxidant capabillity of water extracts from DQ were 27.21mg/g and 22.95mg/g, respectively. The DQ water extract showed highest antioxidant activity by DPPH and ABTS scavenging activities. The DQ water extract was protected cells against H₂O₂-induced cell death without any cytotoxicity, as determined by the MTT assay. The DQ water extract also was inhibiting production of intracellular ROS. Conclusion : These observations suggest that DQ can use potentially good natural antioxidant in daily life for possible health benefits.

The objectives of this study were to identify QTLs for agronomic traits using introgression lines from a cross between a japonica weedy rice and a Tongil-type rice. A total of 75 introgression lines developed in the Tongil-type rice were characterized. A total of 368 introgressed segments including 285 homozygous and 83 heterozygous loci were detected on 12 chromosomes based on the genotypes of 136 SSR markers. Each of 75 introgression lines contained 0-9 homozygous and 0-8 heterozygous introgressed segments with an average of 5.8 segments per line. A total of 31 quantitative and 2 qualitative loci were identified for 14 agronomic traits and each QTL explained 4.1% to 76.6% of the phenotypic variance. Some QTLs were clustered in a few chromosomal regions. A first cluster was located near RM315 and RM472 on chromosome 1 with QTLs for 1,000 grain weight, culm length, grain width and thickness. Another cluster was detected with four QTLs for 1,000 grain weight, grain length, grain width and grain length/width ratio near the SSR marker RM249 on chromosome 5. Among the 31 QTLs, 9 (28.1%) Hapcheonaengmi3 alleles were beneficial in the Milyang23 background. ILs would be useful to confirm QTLs putatively detected in a primary mapping population for complex traits and serve as a starting point for map-based cloning of the QTLs. Additional backcrosses are being made to purify nearly isogenic lines (NILs) harboring a few favorable Hapcheonaengmi3 alleles in Milyang23 background.