As unit 1 of Kori was permanently shut down in June 2017, domestic nuclear industry has entered the path of decommissioning. The most important thing in decommissioning is cost reduction. And volume reduction of radioactive waste is especially important. According to the IAEA report, more than 4,000 tons of metallic waste is generated during the decommissioning of a 1,000 MWe reactor and most of these wastes are LLW or VLLW. To reduce amount of metallic waste dramatically, we should choose efficient decontamination method. In this study, we conducted dry ice and bead blasting decontamination. We prepared Inconel-600 and STS-304 specimen with dimensions of 30 mm × 30 mm × 5 mm. Loose and fixed contamination was applied on the surface of specimen using SIMCON method. Bead and dry-ice blasting was conducted by spraying alumina and dry ice pellet at the same pressure and distance for the same time. The removal of loose contamination was observed using microscope. It was found that contaminants are significantly removed using both dry ice blasting and bead blasting. However, some abrasive material remained on the surface of specimen. The removal of fixed contamination was verified by weight comparison before and after experiment and cobalt concentration comparison before and after experiment using X-ray Fluorescence Spectroscope (XRF). At least 90% of the cobalt was removed, but some abrasive particle was also remained on the surface of specimen. In this study, it is confirmed that the effectiveness of manufacturing a large-scale abrasive decontamination facility, and it is expected that this technology can be used to effectively reduce the amount of metallic waste generated during decommissioning.

Effects of Oplopanax elatus have known to various pharmaceutical therapies. However, chemical prosperities in the plant are rarely investigated. In order to detect biological activity, we evaluated the antioxidant activity of five fractions from methanolic extracts in each part of O. elatus. Also, contents of polyphenols and polysaccharides were measured. Five fractions were of sub-fractions using n-hexane, ethyl-acetate, n-butanol, and water from methanolic extracts. Ethylacetate and n-butanol fractions from stem and root exhibited strong antioxidant activity and high total phenolics content. On the HPLC analysis, ten free phenolics, including p-hydroxybenzoic acid, chlorogenic acid, caffeic acid, syringic acid, p-cou maric acid, ferulic acid, naringin, hesperidin, quercetin and trans-cinnamic acid, were identified from the fractions and were shown to different quantitative proportions. Furthermore, ethylacetate and n-butanol fraction had the highest amount of chlorogenic acids, one of the cinnamic acid derivatives possessing pharmacological properties. These results indicated that the fractions of O. elatus, as well as methanolic extracts, could be used as natural antioxidative ingredients.