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Plastic recycling and material flow of packaging expanded polystyrene by EPR in South Korea
( Hakyun Song ),( Youngsun Kwon ),( Yong-chul Jang ),( Byeonghwan Kim ),( Dong Gyu Shin ),( Yongseon Lee ) 한국폐기물자원순환학회 2022 ISSE 초록집 Vol.2022 No.-
Expanded polystyrene (EPS) is one of the thermoplastic polymers that are widely used in many industrial applications such as insulation, packaging, aquaculture floats, and buoys. Since it has the property of easy material decomposition into small microplastics under natural environment, stringent management measures for such materials are urgently required. In this study, material flow analysis (MFA) was conducted to determine quantitative flows of the materials by life cycle (manufacturing, use, collection, recycling and disposal). Based on the results, the predicted EPS consumption by 2030 was estimated using several linear regression methods. In 2019, approximately 47,000 tons of packaging EPS out of total 337,000 ton EPS were consumed and distributed in Korea. About 53,000 tons of waste EPS forms were collected by recycling waste streams, out of which 41,900 tons were recycled as ingot (40,871 tons), fire-resistance coatings for steel frames (1,521 tons), and pellet (287 tons). By using the regression analysis, from 2003 to 2019, the amount of EPS consumption was steadily increased, and the cumulative amount of EPS recycling by the period was estimated to be about 412,000 tons by 2030. This study evaluated the potential benefits of resource savings and reduction of greenhouse gas emissions through EPS packaging recycling.
Study on the Effect of Pressurizer Cutting Scenario
Hakyun Lee,Sunil Kim,Minho Lee,Jongsoon Song 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1
When a permanently-closed nuclear power plant is to be decommissioned, large structures targeted to be cut in the process include a steam generator, reactor, and reactor coolant pump (RCP). Although there are sufficient preliminary studies being done on these structures to assess the radiation exposure dose, relatively fewer studies are underway regarding pressurizers. Therefore, preliminary evaluations are required to prevent workers from being overexposed to radiation coming from a pressurizer and to avoid an unnecessary increase in the decommissioning cost. This study created a cutting scenario based on disposal drums for solid radioactive wastes. The cutting scenario was based on 200-liter and 320-liter drums for solid wastes and on the assumption that all cutting operations were done 100 centimeters away from the structure to be cut. When are cutting process of a Pressurizer is carried out per scenario, the 200-liter drum produces 272 pieces, whereas the 320-liter counterpart generates 234 pieces. Given that South Korea allocates 75,550 KRW per liter (based on 200 L) for the disposal cost, an increase in the number of drums leads to an exponential growth of the decommissioning cost, which fuels the need to establish more organized cutting strategies. Meanwhile, in terms of radiation dose, plasma, laser, and flame cutting techniques were estimated to record 0.232 mSv, 0.299 mSv, and 0.213 mSv respectively for 200 L, and 0.195 mSv, 0.251 mSv, and 0.179 mSv respectively for 320 L (based on DF-90). When compared with the annual dose limit of 100 mSv (0.0057 mSv·hr?1), the above numbers registered for both 200 L and 320 L were estimated to satisfy the dose limit, with only a negligible difference in the dose between the two capacities. The results generated from this study are expected to be utilized as a meaningful basis to identify applicable cutting techniques of a pressurizer as part of the decommissioning operation and to establish its cutting plans in compliance with ALARA.
Recycling practice and targets of PET bottles by EPR towards a circular economy in South Korea
( Youngsun Kwon ),( Byeonghwan Kim ),( Yong-chul Jang ),( Hakyun Song ),( Kyunghoon Choi ),( Dong Gyu Shin ),( Yongseon Lee ) 한국폐기물자원순환학회 2022 ISSE 초록집 Vol.2022 No.-
Polyethylene terephthalate (PET) is one of the commonly used plastic packaging materials. Improper disposal of PET bottles may create plastic pollution in oceans and rivers and streams. In Korea, the collection and recycling of used PET bottles has been managed by Extended Producer Responsibility (EPR) system since 2003. In this study, material flow analysis for PET bottles was carried out to elucidate its quantitative flow for collection and recycling. Also, based on the analysis, in 2018, approximately 236 thousand tons of used PET bottles were recycled, while only 30 thousand tons were used as high-grade recycled materials (sheet and bottles), and about 206 thousand tons were used as low-grade recycled materials (e.g., fiber, strings). It is expected that more than 500,000 ton of PET bottles will be consumed in 2030 with an assumption 5% annual increase. In order to accelerate high-quality PET recycling, mandatory recycled content of PET bottles would be required in the future, as many EU countries are adopting the requirement. As a result of greenhouse gas reduction using WARM, in 2030, more than 373,000 ton CO<sub>2</sub>eq could be reduced with the assumption of 30% recycled content use in PET bottles. This study proved the potential benefits of PET bottle recycling by providing the amount of greenhouse gas reduction as well as material recycling toward a circular economy in South Korea.