In this study, the current situation of recycling domestic and foreign metal clearance waste was reviewed to suggest the optimal recycling scenario for metal clearance waste that occurs the most when decommission nuclear power plants. Factors that can directly or indirectly affect the recycling of metal clearance waste were analyzed and evaluation criteria that can be used to evaluate optimal recycling measures were prepared. Using this, a scenario for recycling the optimal metal clearance waste suitable for the domestic environment was proposed. As a result of comparing/reviewing the importance of the first level of the evaluation criteria, public acceptance, national policy, and regulatory requirements were evaluated as the most important ones, and recycling acceptance and regulatory requirements were evaluated as the most important the second level of evaluation criteria. As a result of reviewing the clearance waste recycling scenario, it was evaluated that unrestricted recycling scenario was preferred. This may be because the survey subjects are composed of experts in the nuclear power field, so they know recycling of clearance waste in general industries does not significantly affect radiation safety. However even if it is clearance waste, the public may feel reluctant to recycle just because it was discharged from nuclear power plants, so policy and institutional improvements are needed to reassure the public along with the scientific safety of clearance waste. In addition, in order to improve public acceptance, it seems necessary to prepare specific measures to ensure the participation of public in the entire decommissioning process, share related information, and disclose all routes from generation to disposal of decommissioning waste. Considering that research on domestic clearance waste recycling options has not been activated, this study is significant in that it derives a scenario for recycling metal clearance waste that can be implemented. Also, it is expected that the evaluation criteria derived from this study will be used significantly when establishing a radioactive waste management strategy.

In this study, we investigate the recycling of aluminum-based metal matrix composites(AMCs) embedded with SiC particulates. The microstructure of the AMCs is characterized by X-ray diffraction and scanning electron microscopy. The possibility of recycling the composite scrap is attempted from the melted alloy and SiC particulates by re-melting, holding and solidification in crucibles. The recovery percentage of the matrix alloy is calculated after a number of holding times, 0, 5, 10, 15, 20, 25 and 30 minutes and for different particulate sizes and weight fractions in the Al matrix. The results show that the recovery percentage of the matrix alloy, as well as the time required for maximum recovery of the matrix, is dependent on the size and weight fraction of SiC particulates. In addition, the percentage recovery increases with particulate size but drops with the particulate fraction in the matrix. The time to reach maximum recovery falls rapidly with an increase in particulate size and fraction.

Owing to increasing demand of rare metals present in ICT products, it is necessary to promote the rare metal recycling industry from an environmental viewpoint and to prevent climate change. Despite the fact that information for toxic substances is partly indicated, a legal basis and an international standard indicating usage of rare metals is insufficient. In order to address this issue, a newly created study group of environment and climate change at the ITU (International Telecommunication Union) is doing research to develop methodologies for recycling rare metals from ICT products in an eco-friendly way. Under this group, the Republic of Korea has established two international standards related to rare metals present in ICT products. The first is ‘Release of rare metal information for ICT products (ITU-T L.1100)’ and the other is ‘Quantitative and qualitative analysis methods for rare metals (ITU-T L.1101)’. A new proposal for recommending the provision of rare metal information through a label by manufacturers and consumer/recycling businesses has been approved recently and is supposed to be published later in 2016. Moreover, these recommendations are also being extended to IEC, ISO and other standardization organizations and a strategy to reinforce the ability for domestic standardization is being established in accordance with industrial requirements. This will promote efficient recycling of rare metals from ICT products and will help improve the domestic supply of rare metals.

A study on the possibility of recycling by solidification using tailings from abandoned metal mine were studied. The study was carried out on testing compressive strength of concrete made by different ratio of various mine tailing, chemical speciation of Cd, Cu, Pb and Zn in the tailing by sequential extraction procedure and SPLP leaching test. Mixing of mine tailings with cement or asphalt and aging of mortar gave strong influence on compressive strength of concrete. Marshal's stability of asphalt with tailing waste were higher of 98.0~101.0% than not added one. Therefore it was recommended to use of the tailings to low the infiltlation of the water to protect the bank in the abandoned mine region. Total metals in concrete and asphalt with tailing waste were lower than that of tailing waste. The amount of adsorbed fraction and carbonate fraction which were labile in the aquatic environment were very lower in the concrete and asphalt specimen than mine tailing waste.Leachabilityof studied metals are under the waste management standard.

원자력시설의 해체 시 발생되는 금속폐기물의 양은 전 세계적으로 향후 50년 동안 스테인레스강 약 95 만톤, 탄소강 870 만 톤, 구리 220 만 톤으로 총 1,200 만 톤 정도 발생할 것으로 예측되고 있다. 해체 시 발생하는 금속 조각은 대부분 방사능에 아주 미미하게 오염되어 있기 때문에 이중에서 대부분은 무구속 방출이나 약간의 제염 처리 후 일정한 공정을 거쳐 핵 시설내의 폐기물 저장 용기나 처분 상자, 폐기물 드럼, ISO 컨테이너 등으로 재활용되고 있거나, 앞으로 재활용할 수 있다고 보고되고 있다. 국내 원자력시설 해체 시 다량으로 발생될 것으로 예상되는 금속 조각을 수용하기에는 폐기물 처리장이 매우 부족할 뿐만 아니라, 지속적으로 처분 단가의 증가가 예상되므로 이러한 문제를 해결하기 위해서 방사성 금속폐기물의 효과적인 감용 및 재활용 기술이 요구되고 있다. 금속 폐기물의 감용 및 재활용 기술 중 현재까지 가장 적절한 기술로서 용융 기술이 있다. 유럽을 주축으로 미국과 일본에서 활발히 연구되어져 온 용융 기술은 다른 처분 방법에 비해 부피 감용비가 가장 높아 최종처분시설 공간을 절약할 수 있으며 탄소강, 스테인레스강 및 인코넬 등 많은 양의 금속을 회수하는 것이 가능하다. 또한, 이 기술은 휘발성 핵종(Cs 등)이나 금속과 반응성이 적은 핵종(U, Pu 등)을 슬래그 속에 포집하여 제염하거나, 방사성 핵종들이 주괴에 균일하게 분포하고 금속의 결정 격자속에 고정화시킬 수 있기 때문에 보다 안정화시킬 수 있다는 장점들을 가지고 있다.