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 Korea, it is expected that the decommissioning of nuclear reactors will increase due to the license termination of reactors constructed in the 1960s to the 80s. According to the investigation of KORAD, VLLW accounts for 67.10% of decommissioning wastes and amounts to about 413,336 drums. Due to their huge amount, it is necessary to create an appropriate decommissioning waste management plan even though VLLW is disposed at the second-phase disposal facility of the Gyeongju repository. For efficient reduction in decommissioning wastes, it is required to actively use a clearance of metallic and concrete radioactive wastes. Regulations of nuclear safety and security commission notice that the radioactive waste can be reused or recycled if it meets the clearance criterion, 10 μSv·y−1 for individual dose. Therefore, it is important to develop a computational code which calculate individual doses for each scenario, and determine whether the clearance criterion is satisfied. However, in the case of metallic waste, RESRAD-RECYCLE used in dose assessment for the clearance has no longer been maintained or updated since 2005 and there is no code for recycling of concrete waste. For this reason, a dose assessment code RUCAS (Recycle-Underlying Computational dose Assessment System) has been developed by Ulsan National Institute of Science and Technology (UNIST). A point kernel method is adopted into external dose assessment model to calculate more realistic options, which are various geometries of source, and shielding effect. In the case of internal radiation, equations of internal dose from IAEA are used. This research conducts a verification of dose assessment model for recycling of metallic radioactive waste. RESRAD-RECYCLE is the comparison object and results from RESRAD-RECYCLE validation report are referenced. Targets are 14 recycling scenarios composed up to the smelting metal step of four steps, which are arising scrap metal, smelting scrap metal, and fabrication of metal product, and reusing/recycling of product. Seven isotopes, which are Ac-227, Am-241, Co-60, Cs-137, Pu-239, Sr- 90, and Zn-65, are selected for calculation. Validation results for external dose vary by isotopes, but show acceptable differences. It seems to be caused by difference in the calculation method. In the case of internal dose using same calculation formula, results are exactly matched to RESRAD-RECYCLE for all isotopes. Consequently, RUCAS can conduct functions supported by RESRAD-RECYCLE well and future work will be conducted related to domestic recycling scenarios considering public acceptance, and verification with radiation shielding codes for various geometries of source.

Rare earth elements, which are important components of motors, are in high demand and thus constantly get more expensive. This tendency is driven by the growth of the electric vehicle market, as well as environmental issues associated with rare-earth metal manufacturing. TC 298 of the ISO manages standardization in the areas of rare-earth recycling, measurement, and sustainability. Korea, a resource-poor country, is working on international standardization projects that focus on recycling and encouraging the domestic adoption of international standards. ITU-T has previously issued recommendations regarding the recycling of rare-earth metals from e-waste. ISO TC 298 expands on the previous recommendations and standards for promoting the recycling industry. Recycling-related rare earth standards and drafts covered by ISO TC 298, as well as Korea’s strategies, are reviewed and discussed in this article.

Tungsten carbide is widely used in carbide tools. However, its production process generates a significant number of end-of-life products and by-products. Therefore, it is necessary to develop efficient recycling methods and investigate the remanufacturing of tungsten carbide using recycled materials. Herein, we have recovered 99.9% of the tungsten in cemented carbide hard scrap as tungsten oxide via an alkali leaching process. Subsequently, using the recovered tungsten oxide as a starting material, tungsten carbide has been produced by employing a self-propagating high-temperature synthesis (SHS) method. SHS is advantageous as it reduces the reaction time and is energy-efficient. Tungsten carbide with a carbon content of 6.18 wt % and a particle size of 116 nm has been successfully synthesized by optimizing the SHS process parameters, pulverization, and mixing. In this study, a series of processes for the highefficiency recycling and quality improvement of tungsten-based materials have been developed.

Because of its unique properties, tungsten is a strategic and rare metal used in various industrial applications. However, the world's annual production of tungsten is only 84000 t. Ammonium paratungstate (APT), which is used as the main intermediate in industrial tungsten production, is usually obtained from tungsten concentrates of wolframite and scheelite by hydrometallurgical treatment. Intermediates such as tungsten trioxide, tungsten blue oxide, tungstic acid, and ammonium metatungstate can be derived from APT by thermal decomposition or chemical attack. Tungsten metal powder is produced through the hydrogen reduction of high-purity tungsten oxides, and tungsten carbide powder is produced by the reaction of tungsten powder and carbon black powder at 1300–1700oC in a hydrogen atmosphere. Tungsten scrap can be divided into hard and soft scrap based on shape (bulk or powder). It can also be divided into new scrap generated during the production of tungsten-bearing goods and old scrap collected at the end of life. Recycling technologies for tungsten can be divided into four main groups: direct, chemical, and semi-direct recycling, and melting metallurgy. In this review, the current status of tungsten smelting and recycling technologies is discussed.

남아시아 지역 선박재활용에서 발생하는 인권침해 문제는 2000년 초반부터 지속적으로 제기되어져 왔다. 국제사회는 이러한 인권문제에 대응하기 위하여 선박재활용을 위한 선박수출을 바젤협약을 통해 규제해왔다. 그러나, 주요 해운선진국에 소재한 선주들은 바젤협약을 통한 규제를 편의치적 제도와 대리인을 통해 우회하여 제도권을 벗어난 선박재활용을 지속적으로 시행해 오고 있다. 따라서 본 논문에서는 현 제도의 한계점을 인식하고 선박재활용을 규제하기 위한 유엔인권법상 국가의무를 검토하였다. 실제, 유엔인권법은 인권침해를 야기하는 기업행위는 규제되어야 한다고 명시하고 있다. 이러한 유엔인권법상 의 규제제도는 과거 역사적인 이유로 주로 통치자 혹은 개인에게 주로 적용되어져 왔다. 하지만, 최근 다국적 기업의 인권침해 현상은 세계화와 더불어 급증하고 있으며, 이를 규제하기 위한 제도적 합의가 필요하기에 이르렀고, 유엔은 2011년 “인권과 기업에 관한 유엔인권지침”을 채택하였다. 동 지침은 유엔인권 법상 규정된 사항을 다국적 기업과 국가 관계에서 어떻게 적용할지를 다루는 법원칙을 서술하고 있다. 따라서, 남아시아에서 실시하는 대형선의 선박재활용이 대다수 다국적 해운기업의 요청에 따라 시작된다는 점에 착안하여 이러한 해운기업을 규제하기 위하여 유엔인권법상의 국가의무가 어떤 것이 있는지 본 논문에서 분석하였으며, 그리고 이러한 국가의 의무를 선박재활용과 관련하여 어떻게 적용할 수 있을 것인지 본 논문에서 살펴보았다.

The objectives of this study were: (1) to identify differences in consumer attitudes and intentions to recycle fashion products using three types of recycling (including resale, reform, and donation), and (2) to examine the moderating effects of consumer prosocialness on the relationships between attitude and intention for each type of fashion product recycling. Men and women aged 20 years and over were recruited from a marketing research firm panel. Participants completed an online questionnaire incorporating measures for attitudes and intentions to resale, reform, and donate fashion products, prosocialness, frequency of purchasing fashion products, monthly amount of spending on fashion products, and demographic information. Data from 224 participants were analyzed using SPSS 25.0 and PROCESS macro. The results demonstrated that consumers had significantly different attitudes and intentions depending on type of fashion product recycling. Consumers had more positive attitudes toward donation compared to resale and reform types of recycling. Consumer intentions toward resale and donation were significantly higher than their intention to reform. Furthermore, this study confirmed that the attitude-intention gap in fashion product recycling can be explained by individual prosocialness. The moderating effects of prosocialness on the associations between attitude and intention to recycle were significant. The implications of increasing consumers’ behavior intention to recycle fashion products was discussed and future research suggestions are provided.

In this study, a chlorination technique for recycling Li2ZrO3, a reaction product of ZrO2-assisted rinsing process, was investigated to minimize the generation of secondary radioactive pyroprocessing waste. It was found that the reaction temperature was a key parameter that determined the reaction rate and maximum conversion ratio. In the temperature range of 400−600℃, an increase in the reaction temperature resulted in a profound increase in the reaction rate. Hence, according to the experimental results, a reaction temperature of at least 450℃ was proposed to ensure a Li2ZrO3 conversion ratio that exceeded 80% within 8 h of the reaction time. The activation energy was found to be 102 ± 2 kJ·mol−1·K−1 between 450 and 500℃. The formation of LiCl and ZrO2 as reaction products was confirmed by X-ray diffraction analysis. The experimental results obtained at various total flow rates revealed that the overall reaction rate depends on the Cl2 mass transfer rate in the experimental condition. The results of this study prove that the chlorination technique provides a solution to minimize the amount of radioactive waste generated during the ZrO2-assisted rinsing process.

알코올성 용제를 재활용할 수 있는 목적의 유기용제나노여과막(OSN)을 내용제성이 우수한 폴리벤지다졸 고분자를 이용하여 비용매 유도 상분리법을 이용하여 제조하였다. 제조한 나노여과막의 모폴로지와 투과특성을 조절하기 위하여 도프 용액의 농도와 물과 에탄올의 혼합용액인 응고액의 조성을 변화시키면서 제조하였다. α,α’-dibromo-p-xylene (DBX)을 이용하여 가교한 폴리벤지미다졸 분리막은 유기용제나노여과막으로 사용하기에 충분한 기계적 강도와 내용제성을 갖는 것을 확인하였다. 물로만 이루어진 응고조에서 도프용액의 농도가 20%이상인 분리막을 제조하는 경우에 분자량 696.66 g/mol을 가지는 콩고레드에 대한 제거율은 90% 이상을 나타내었고, 투과도는 5 bar의 압력에서 22.5 LMH/bar를 나타내었다. 응고액 조성에 대한 연구를 통해서 응고액 중의 에탄올 농도가 증가할수록 에탄올의 투과도가 증가하는 것을 확인하였다.

본 연구에서는 선박용 디젤 엔진에서 발생되는 크랭크케이스 수트(soot)의 재활용 가능성을 검토하기 위하여, 수트를 배기관에서 발생하는 수트와 크랭크케이스에서 발생한 수트로 분류하고, 열처리에 따른 수트의 구조적 특성을 분석하였다. 열처리는 아르곤 가스 분위기에서 2,000℃와 2,700℃로 열처리를 수행하였고, 샘플의 구조적 특성 분석을 위해 라만분광법(Raman spectroscopy)과 고분해능 전자현 미경(HRTEM)을 활용하였다. 또한, 취득한 HRTEM 이미지를 정량적으로 분석하기 위해 디지털 이미지 처리(Digital Image Processing) 기법을 활용하였다. 라만 분석 결과, 배기 수트와 2,700℃로 열처리한 수트에서 상대적으로 높은 G/D ratio가 나타났다. HRTEM 이미지에서는 두 수트 모두 유사한 형태의 흑연화된 나노 구조를 확인할 수 있었으나, 수트의 종류와 열처리 온도차에 따른 흑연화 정도의 차이를 정량 적으로 도출할 수 없는 한계가 있었다. 이에 Digital Image Processing을 통해 HRTEM 이미지의 fringe의 길이와 곡률을 정량적으로 분석하였으며, 라만 분석과 일치하는 결과를 도출할 수 있었다. 이는 배기 수트가 크랭크케이스 수트에 비해 더 흑연화 된 구조를 가지는 것을 의미하며, 더 높은 온도에서 열처리 할 경우 흑연의 구조로 더 잘 발달함을 의미한다. 본 연구의 결과로 크랭크케이스 수트 역시 배기 수트 와 마찬가지로 흑연계 재료로 재활용이 가능함을 확인하였다.