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        검색결과 7

        1.
        2023.05 구독 인증기관·개인회원 무료
        As the importance of radioactive waste management has emerged, quality assurance management of radioactive waste has been legally mandated and the Korea Radioactive Waste Agency (KORAD) established the “Waste Acceptance Criteria for the 1st Phase Disposal Facility of the Wolsong Lowand Intermediate-Level Waste Disposal Center (WAC)”, the detailed guideline for radioactive waste acceptance. Accordingly, the Korea Atomic Energy Research Institute (KAERI) introduced a radioactive waste quality assurance management system and developed detailed procedures for performing the waste packaging and characterization methods suggested in the WAC. In this study, we reviewed the radioactive waste characterization method established by the KAERI to meet the WAC presented by the KORAD. In the WAC, the characterization items for the disposal of radioactive waste were divided into six major categories (general requirements, solidification and immobilization requirements, radiological, physical, chemical, and biological requirements), and each subcategories are shown in detail under the major classification. In order to satisfy the characterization criteria for each detailed item, KAERI divided the procedure into a characterization item performed during the packaging process of radioactive waste, a separate test item, and a characterization item performed after the packaging was completed. Based on the KAERI’s radioactive waste packaging procedure, the procedure for characterization of the above items is summarized as follows. First, during the radioactive waste packaging process, the characterization corresponding to the general requirements (waste type) is performed, such as checking the classification status of the contents and checking whether there are substances unsuitable for disposal, etc. Also, characterization corresponding to the physical requirements is performed by checking the void fraction in waste package and visual confirmation of particulate matter, substances containg free water, ect. In addition, chemical and biological requirements can be characterized by visually confirming that no hazardous chemicals (explosive, flammable, gaseous substances, perishables, infectious substances, etc.) are included during the packaging process, and by taking pictures at each packaging steps. Items for characterization using separate test samples include radiological, physical, and chemical requirements. The detailed items include identification of radionuclide and radioactivity concentration, particulate matter identification test, free water and chelate content measurement tests, etc. Characterization items performing after the packaging is completed include general requirements such as measuring the weight and height of packages and radiological requirements such as measurements of surface dose rate and contamination, etc. All of the above procedures are proceduralized and managed in the radioactive waste quality assurance procedure, and a report including the characterization results is prepared and submitted when requesting acceptance of radioactive waste. The characterization of KAERI’s radioactive waste has been systematically established and progressed under the quality assurance system. In the future, we plan to supplement various items that require further improvement, and through this, we can expect to improve the reliability of radioactive waste management and activate the final disposal of KAERI’s radioactive waste.
        2.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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.
        4,000원
        6.
        1993.09 KCI 등재 서비스 종료(열람 제한)
        Extreme environments and freak wave characteristics in the coastal waters of Korean Peninsula are analyzed using the observed wave data. Freak wave has been intensely emphasized as an important environmental force parameter in several recent research works. However, the mechanism and occurrence probability of freak wave are not clarified. The aims of this study are: to summarize the distribution of extreme environment for wind waves, and to find occurrence probability of freak wave in the coastal waters of Korean Peninsula. These extreme sea conditions are discussed by applying extreme value analysis method, and the statistic characteristics are summarized which can be used to the design and analysis of coastal structures. The mechanism and the occurrence probability of freak wave are also discussed in detail using wave parameters in considered with wave deformation in the coastal waters.