Development of RUCAS: Verfication of Dose Assessment Model for Recycling Scenarios With Shielding Compared With RESRAD-RECYCLE and MicroShield®

Ugyu Jeong,Seungmin Ohk,Jaeyeong Park 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

RUCAS (Recycling-Underlying Computational Dose Assessment System), a dose assessment program based on the RESRAD-RECYCLE framework, is designed to evaluate dose for recycling scenarios of radioactive waste in metals and concrete. To confirm the validity of the recycling scenarios provided by RUCAS, comparative evaluations will be conducted with RESRAD-RECYCLE for metal radioactive waste recycling scenarios and with MicroShield® for concrete radioactive waste recycling scenarios. In the evaluation of metal recycling scenarios without shielding, RUCAS showed similar results when compared to both MicroShield® and RESRAD-RECYCLE. This validates the function of dose assessments using RUCAS for metal recycling scenarios. However, when shielding was present, RUCAS produced results that were comparable to MicroShield®, but differed from those of RESRAD-RECYCLE. The underestimation of dose values up to 1.66E+08 times difference by RESRAD-RECYCLE could potentially decrease reliability and safety in evaluated doses, further emphasizing the importance of RUCAS. Because validation is also necessary for the expanded calculation capabilities resulting from methodological changes of RUCAS (i.e., various radiation source geometries), based on prior validations, it was determined that additional validations are required for different radiation source materials and shielding conditions. In case where the radiation source and shielding materials were identical, RUCAS and MicroShield® produced similar results according to both the Kalos et al. (1974) and Lin and Jiang (1996) methodologies. This demonstrates that the that differences in methodology are inconsequential when considering the same source and shielding materials. However, when the atomic number of the radiation source materials was larger than that of shielding material (HZ-LZ condition), RUCAS obtained results similar to MicroShield® only for the Kalos et al. (1974) methodology. While Lin and Jiang (1996) methodology yield higher results than MicroShield®. Lastly, in case where the atomic number of the radiation source material was smaller than that of the shielding material (LZ-HZ condition,) both methodologies yielded results comparable to MicroShield®. In conclusion, the validity of RUCAS’s shielding calculations has been verified, confirming improvements in dose assessment compared to RESRAD-RECYCLE. Additionally, we observed that shielding effectiveness calculations differ depending on the methodology of build-up effect. If the validity of these methodologies is confirmed, it is expected that selecting the most advantageous methodology for each condition will enable more rational dose assessments. Consequently, in future research, we plan to evaluate the validity of Lin and Jiang (1996) methodology using particle transport codes based on the Monte Carlo method, such as MCNP and Geant 4, rather than MicroShield®.

A Case Study on the Decontamination Reuse and Recycle of Contaminated Metal and Concrete for Decommissioning NPP

Jihwan Yu,Hyung-woo Seo,Gi-lim Kim,Junki Baik 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1

Decontamination and Dismantlement (D&D) are of great interest to owner of decommissioning as a large number of old nuclear facilities around the world are either shutdown or soon to be decommissioned. D&D are key steps in the decommissioning of nuclear power plants (NPPs). These activities typically generate a significant volume of radioactively contaminated waste. However, as much as 90% or more of this waste is lightly contaminated metal and concrete that could potentially be cleared for recycle or beneficial reuse, rather than disposed of as radioactive waste. The objective of this study is to provide reference for the application of current technologies to cost-effectively reduce the volume of radioactive waste associated with decommissioning, through review of experiences with decontamination of NPPs materials for unrestricted release, recycle or reuse, Also, highlights the importance of ongoing efforts to harmonize regulations and standards for radioactive waste management globally to enable reuse and recycle of valuable materials generated during decommissioning. The presented results in the balance of this study are organized to align with the sequence of operations for executing reuse or recycle of material for a decommissioning project. Concrete from buildings has most commonly been used for backfill of voids onsite, while metal has most commonly been melted or cleared into the conventional scrap recycling industry. Copper and lead, commonly found in cables and shielding, have high residual value and are thus highly desirable for recycling. Steel and stainless steel, while not inherently valuable, are present in many large components, such that decontamination for recycling can be cost-effective compared to disposal as radioactive waste. The decontamination techniques range from simple, inexpensive methods to complex, aggressive methods, each with advantages in various scenarios and limitations in others. Treatment often involves the sequential application of two or more decontamination techniques (e.g., chemical decontamination followed by abrasive blasting). Strategies for the characterization of materials for recycling include analyzing material in place before dismantlement, analyzing removed samples before or after dismantlement, and evaluating bulk material removed after dismantlement. If clearance and recycling are permitted, metals can be released to the conventional scrap recycling market, and concrete rubble can be used as backfill material onsite. In general, successful reuse/recycle projects require consideration of reuse/recycling objectives and implementation of associated planning activities early in the decommissioning process. The practicality of reuse/recycle depends on a number of high level (country and region-specific) and component level (material and case specific) factors. Since this information is useful to those responsible for planning or implementing the decommissioning of nuclear facilities, it is expected that it will be of great help especially to those in charge of decommissioning plan and managers in charge of decommissioning projects.

지속가능성의 관점으로 본 리사이클 디자인에 대한 고찰

원윤정(Won, Yoon-Jung),진보라(Jin, Bo-ra),김동윤(Kim, Dong-Yun) 한국실내디자인학회 2014 한국실내디자인학회 학술대회논문집 Vol.2014 No.5

As the human’s life becomes convenient, the problem of disposing mass trash and resource exhaustion problem are becoming serious. As an alternative to these problems, the recycle and recycled design are emerging as a big concern. This study is designed to examine the concept of recycle design and necessity and consider the methodology of the sustainable design focusing the environment-friendly design through the case of furniture reborn by recycling. Also, as the awareness on the recycle design changes positively and new values on the environment are created, people are expected to recognize human and environment coexist.

보문: 모발폐기물의 재활용에 관한 인식 및 발전방안

오세옥 ( Se Ok Oh ),김성남 ( Sung Nam Kim ),박두현 ( Doo Hyun Park ) 대한미용학회(구 대한미용과학회) 2011 대한미용학회지 Vol.7 No.2

Human hairs that must grow continuously until one`s life span is expired function biologically as a scalp protector against environmental variations and utilize aesthetically as an expression technique. The growing hairs that are cut for expression and maintenance of appearance have been wasted without recycle. Theoretically, human hairs that are composed mainly of proteins, lipids, and nucleic acids are very stable structurally not to be degraded biologically and physicochemically under natural condition. Accordingly, the waste human hair may be a source for soil contamination by landfill and air contamination by burning. In this study, the possibility and means for recycle of the waste human hair was carried out a survey targeting ordinary people and beauty experts. As a result of analysis, awareness of beauty experts for recycle of the waste hair turned out to be positive, which was increased in proportion to their job position, work experience, and service length of the beauty experts. The preference of beauty experts for recycle of the waste hair was the fertilizer, which was not influenced by the social location of the working places of the beauty experts. Meanwhile, the perception of beauty experts for recycle of the waste hair was more positive than that of the ordinary peoples, by which the awareness for recycle of waste human hairs is considered to be changed actively in the future. Conclusively, we want this study to be a footstone for development of beauty industry and solution of environmental problem caused by the waste human hair by the paradigm shift in the future.

A Study of Product Design using Recycled Materials

Kwan-Bae Kim,Chung Do-Seung,Jung-Sik Jang 한국인터넷방송통신학회 2020 Journal of Advanced Smart Convergence Vol.9 No.1

Plastics that we use and simply throw away have a life span of about 500 years and barely decompose. The practice of producing and using common plastics needs to be challenged. Until now, they have been useful in the industrial structure of mass production, but it can be said that there is a lack of research into new materials to introduce and apply in terms of material recycling. As a result of this, we have come to the uncomfortable realization of the fact that we cannot incinerate or reuse these precious resources indiscriminately. No matter how well-designed a product is, it has a competitive advantage if production and consumption activities, waste, collection, sorting and treatment are considered in terms of a continuous cycle, and in this respect, Extended Producer Responsibility (EPR) can help. We are implementing the EPR system, and active industrialization in the field of recycling is required, which is also a challenge for producers to participate actively in recycling and seek to save and recycle resources in design and manufacturing. Against this backdrop, We would like to examine the possibilities, through various studies and developments on product design of recyclable materials, which is being conducted mainly in Europe. In particular, we would like to examine the methods, and value of solving environmental problems and the active efforts to achieve this in the design world, and in particular the case of product design using recycled plastics.

CO₂ 재순환형 산소연소 가열시스템개발에 관한 실험적 연구

정유석(Yu-Seok Jeong),이은경(Eun-Kyung Lee),고창복(Chang-Bok Go),장병록(Byung-Lok Jang),한형기(Hyung-Kee Han),노동순(Dong-Soon Noh) 한국연소학회 2006 KOSCOSYMPOSIUM논문집 Vol.- No.-

An Experimental study was conducted on CO₂ recycle combustion heating system using pure oxygen instead of conventional air as an oxidant, which is thereby producing a flue gas of mostly CO₂ and water vapor(H₂O) and resulting in higher CO₂ concentration. The advantages of the system are not only the ability to control high temperatures characteristic of oxygen combustion with recycling CO₂, but also the possibility to reduce NOx emission in the flue gas. A small scale industrial reheating furnace simulator and specially designed variable flame burner were used to characterize the CO₂ recycle oxy-fuel combustion, such as the variations of furnace pressure, temperature and composition in the flue gas during recycle. It was found that CO₂ concentration in the flue gas was about 80% without CO₂ recycle, but increased to 90~95% with CO₂ recycle. The furnace temperature and pressure was decreased due to recycle and the NOx emission was also reduced to maintain under 100ppm.

THE EFFECTS OF HYDRAULIC LOADING RATE AND RECYCLE RATIO ON DENITRIFICATION AND NITRIFICATION FOR LANDFILL LEACHATE BY USING MLE PROCESS

( Jong-choul Won ),( Jung-woo Lee ),( Hwan-kyu Lee ),( Wan Namkoong ),( Cho-hee Yoon ) 한국폐기물자원순환학회 2002 APLAS Vol.2002 No.1

We examined the effects of change in hydraulic loading rate and recycle ratio at the time of biological denitrification and nitrification of leachate containing NH₄⁺-N with high concentration about 1,500-2,000 mg/L which is generated from SUDOKWON landfill site using pilot-scaled MLE(modified ludzack ettinger) process. As a result of this examination, we found out that about 2.3 days in denitrification tank and 5.7 days in nitrification are the proper HRT for obtaining the removal efficiency of about 80 % for T-N and 99% for NH₄⁺ -N at the conditions of recycle ratio of about 600 % and BOD/NH₄⁺ -N ratio of about 3.0. In addition, proper recycle ratio for obtaining the maximum nitrogen removal efficiency while keeping proper microbe concentration in nitrification and denitrification tank was 200 % for external recycle and about 400% for internal recycle. The maximum nitrogen quantities to be removed for each load of T-N and NH₄⁺ -N are 0.055 kgT-N/kgVSS/day and 0.07 kgNH₄⁺ -N/kgVSS/day, respectively. Alkalinity quantity(△ alkalinity/△T-N) to be consumed for removal of T-N was found to be about 5.0.

화학재생 폴리에스터 칩의 물성향상 연구

임대희,오미옥,최연주,김성훈,Lim, Dae Hee,Oh, Mi Ok,Choi, Yeon Joo,Kim, Seong Hun 한국섬유공학회 2013 한국섬유공학회지 Vol.50 No.2

Chemically recycled/virgin poly(ethylene terephthalate) (PET) blends were prepared by melt blending to improve the physical properties of the chemically recycled PET. The effect of virgin PET on the mechanical and thermal properties, molecular weight, and crystallinity of the chemically recycled/virgin PET blends was investigated. The tensile strength and modulus of the chemically recycled/virgin PET blends increased with increasing virgin PET content. The crystallinity of the chemically recycled/virgin PET blends depended significantly on the recycled PET content because of the nucleation effect of the residual catalyst generated from the depolymerization of PET. The color index of the chemically recycled/virgin PET blends was also investigated to determine the color of the blends numerically.

일본의 회수물류와 리사이클제도에 관한 연구

한상훈(Sang Hun Han),김용헌(Yong Heun Kim),박정희(Jung Hee Park) 중앙대학교 한국전자무역연구소 2013 전자무역연구 Vol.11 No.3

일본은 부존자원이 빈약하기 때문에 자원의 효율적인 이용을 통해 순환형 사회를 만들자는 목표로 순환형 사회형성추진기본법을 시행하여 왔다. 이러한 법률적 근거하에 자동차, 가전, 식품, 건설 등 각종 리사이클법이 제정되었으며, 법률에서 일본뿐만 아니라 외국의 제조업자에게도 리사이클에 대한 책임을 지우고 있어 우리나라의 기업에도 많은 영향을 줄 것으로 예상된다. 따라서 일본의 회수물류와 리사이클제도에 대해 살펴보고 일본의 리사이클제도로 인하여 예기치 못하게 발생하는 손해를 미연에 방지하도록 하는 것이 본 논문의 목적이다. Because of lack of natural resources, Japan has been implementing the Fundamental Law for Establishing a Sound Material-Cycle Society with the aim of establishing a sound material-cycle society through the efficient using of resources. Under this legal basis, Recycling Laws regarding End-of-Life Vehicles, Home Appliances, Food Wastes, Construction Materials were enacted and it may be expected to give a significant impact to companies in Korea, because the laws require both Japanese manufacturers and overseas manufacturers to assume the responsibility of recycling. Therefore, the purpose of this paper are to study reverse logistics and recycling systems in Japan and to prevent the unexpected damages due to recycling systems in Japan.

재활용되는 폐기물의 소유권 이전과 배출자 책임

김윤승 ( Kim Yun Sung ) 한국환경법학회 2020 環境法 硏究 Vol.42 No.1

최근 「폐기물관리법」이 개정되면서 폐기물배출자에 대한 방치폐기물 처리 책임이 구체화되었다. 한편으로, 연초박을 불법 건조하여 유기질 비료를 생산하는 과정에서 발생한 물질에 의한 암 집단발생이 조사된 바, 재활용되는 폐기물 관리책임의 강화 필요성도 제기된다. 그런데 이와 같은 폐기물 책임의 강화는 자칫 폐기물을 자원으로 보아 지속가능한 자원순환사회로 전환하고자 하는 노력을 방해할 수 있다. 폐기물관리의 원칙이 과거의 포지티브 규제 방식에서 원칙적으로 재활용을 허용하되 예외적인 경우에만 규제하는 네거티브 방식으로 변화하면서, 재활용되는 폐기물에 대해서는 폐기물배출자가 동시에 제품의 원료 공급자로서의 지위를 가지게 되는 경우가 점차 늘어날 것으로 전망되나 현행 법제 하에서는 재활용 제품에 대한 「폐기물관리법」 적용의 종료의 시점이 명확하지 않다. 본고에서는 재활용되는 폐기물을 순환 중인 자원으로 보아 그 소유권¹⁾을 배출자에게 유보하되, 폐기물에서 재활용 원료로 전환되는 시점을 객관적으로 특정하여 폐기물 종료를 선언하고 동시에 폐기물배출자의 소유권 포기와 처리자의 재활용원료 소유권 취득을 인정하여야 할 필요성 및 그 효과에 대해 고찰해 보고자 한다. 이를 위해 우선 「폐기물관리법」의 적용을 종료하더라도 배출자의 사법상 책임 귀속에 있어서 실질적인 차이를 낳지 않음을 보이고자 한다. 다음으로 대법원 2016. 5. 19. 선고 2009다66549 전원합의체 판결의 분석을 통해 재화인 동산에 있어서 소유권자의 배타적 권리를 인정하는 것과 마찬가지로 비재화에 동반되는 책임을 인정하는데 있어서도 배타적 관리 영역을 구분할 필요성이 있음을 짚어본다. 나아가 폐기물에서 재활용 원료로 전환되어 배출자에서 처리자로 소유권이 이전하는 시점의 특정은 폐기물이 객관적으로 환경오염원으로 작용할 수 있는지 여부를 기준으로 하여야 하므로 폐기물의 유해성과 노출경로를 평가하여 위해도(risk)를 예측하는 재활용환경성평가 결과로 판단하도록 하고, 그와 같은 의무를 확대적용하여 배출자에 대한 공사법적 책임 범위를 명확하게 하는 동시에 평가 의무를 다하였을 때는 「폐기물관리법」의 적용을 종료함으로써 재활용되는 폐기물을 일반적인 재화와 마찬가지로 취급하도록 제안하고자 한다. Recently, the Waste Control Act was amended to clarify the neglect waste liability. Also, a cancer cluster was confirmed by a government-led investigation as being caused by substances generated during the production of an organic fertilizer using recycled tobacco waste originated from cigarette factories, and a new amendment of waste liability is expected given regulatory gaps regarding waste recycling. However, more liability may dwindle the policy efforts promoting waste recycling and the circular economy society of zero waste. The Waste Control Act has adopted a negative approach for recycling, allowing recycling of all types of waste with small number of exceptions of a certain categories of hazardous waste and medical waste. Given such policy drive for recycling, it is likely and also desirable that more waste generators become second material producers. However, it is unclear, under the current legislation, when in the recycling process waste changes its status to a product to which the Waste Control Act no longer applies. Regarding recycled waste as circulating resource, the ownership of the waste can be entitled to the generator, which enables conveyance of the ownership to an intended recycling operator. This is viable based on the analysis showing that the end-of-waste status does not make a substantial difference in terms of holding the generator responsible for third party damages. Liabilities associated with “bads”, i.e., waste, can be well defined with property rights similarly as goods with the ownership, and the 2016. 5. 19. Supreme Court en banc Decision 2009Da66549 confirms this. The end-of-waste and subsequent ownership transfer of second material from the generator to a recycling operator must be based on objective criteria to determine whether the waste poses health and environmental risks. Therefore, not only the hazards of the waste, but also the exposure pathways of waste recycling should be characterized by the generator who wishes to gain the end-of-waste status. Once the risks are characterized and the recycling is authorized, an exemption from the Waste Control Act will allow the second material to be treated as movables.