• 대한방사선기술학회지:방사선기술과학
• /
• 제41권1호
• /
• pp.67-73
• /
• 2018

In this paper, risk assessment was conducted to verify self - disposal requirements by landfill for exempted incineration ash by using Resrad Ver.6.5 computer code. The result of risk assessment by landfill for the incineration by-product is that individual dose is $6.91{\times}10^{-2}{\mu}Sv\;y-1$ and collective dose is $3.475{\times}10^{-7}man-Sv\;y-1$. It proved that the result meets reference dose of individual dose $10{\mu}Sv\;y-1$ and collective dose 1 man-Sv y-1 for general public. According to the current 'Nuclear Safety Commission Notice [No. 2014-3]', it states that the exempted wastes can be disposed of by incineration, landfill and recycling. However, most of recently documents and papers related to exempted wastes are disposed of by landfill and recyling and it could not confirm the case of exempt by incineration. If the national consensus is derived and treating the waste by using process of incineration is activated, it could be considered to treat low level of radiation wastewater and activated carbon excluded from exempted waste because of nuclide $^3H$ and $^{14}C$.

• 대한방사선기술학회지:방사선기술과학
• /
• 제44권5호
• /
• pp.481-487
• /
• 2021

This study was conducted for the purpose of efficient radioactive waste disposal and management. Experiment was evaluated the decontamination efficiencies of the four types decontamination materials(Water, Alcohol, Decontamination Water, Decontamination Gel) with radioactive wastes generated during radio-pharmaceutical production process at Korea Institute Radiological and Medical Sciences(KIRAMS). The radioactive waste sample used in experiment is a lead plate of the fume hood that was disposed in April, 2019. In the experimental method, radioactive waste was measured before and after decontamination using a HPGe semiconductor detector and Gamma survey meter. The measured values before and after decontamination were evaluated for decontamination efficiency as a percentage. As a result, it was confirmed that a lot of specific activity and surface dose rate was removed from the radioactive wastes. In particular, when decontamination water was used, most of the radioactivity of radioactive wastes was removed. Considering these results, if decontamination water is used in decontamination of radioactive waste, decontamination efficiency equivalent to the disposition criteria can be expected with just one decontamination treatment. In addition, in the case of water and alcohol, only on decontamination was effective in approximately 75% and 95%. Otherwise, when decontamination gel was used, it was confirmed that the largest deviation occurred among all experimental results.

• 방사선산업학회지
• /
• 제9권4호
• /
• pp.217-221
• /
• 2015

When reactor coolant leaks occur due to cracks of a steam generator's tube, radioactive materials contained in the primary cooling water in nuclear power plant are forced out toward the secondary systems. At this time the secondary water purification resin in the ion exchange resin tower of the steam generator blowdown system is contaminated by the radioactivity of the leaked radioactive materials, so we pack this in special containers and store temporarily because we could not dispose it by ourselves. If steam generator tube leakage occurs, it produces contaminated spent resins annually about 5,000~7,000 liters. This may increase the amount of nuclear waste productions, a disposal working cost and a unit price of generating electricity in the plant. For this reasons, it is required to develop a decontamination process technique for reducing the radioactive level of these resins enough to handle by the self-disposal method. In this research, First, Investigated the structure and properties of the ion exchange resin used in a steam generator blowdown system. Second, Checked for a occurrence status of contaminated spent resin and a disposal technology. Third, identified the chemical characteristics of the waste radionuclides of the spent resin, and examined ionic bonding and separation mechanism of radioactive nuclear species and a spent resin. Finally, we carried out the decontamination experiment using chemicals, ultrasound, microbubbles, supercritical carbon dioxide to process these spent resin. In the case of the spent resin decontamination method using chemicals, the higher the concentration of the drug decontamination efficiency was higher. In the ultrasound method, foreign matter of the spent resin was removed and was found that the level of radioactivity is below of the MDA. In the microbubbles method, we found that the concentration of the radioactivity decreased after the experiment, so it can be used to the decontamination process of the spent resin. In supercritical carbon dioxide method, we found that it also had a high decontamination efficiency. According to the results of these experiments, almost all decontamination method had a high efficiency, but considering the amounts of the secondary waste productions and work environment of the nuclear power plant, we judged the ultrasound and supercritical carbon dioxide method are suitable for application to the plant and we established the plant applicable decontamination process system on the basis of these two methods.

• Safety and Health at Work
• /
• 제2권1호
• /
• pp.9-16
• /
• 2011

The majority of people diagnosed with diabetes mellitus are in the working age group in developing countries. The interrelationship of diabetes and work, that is, diabetes affecting work and work affecting diabetes, becomes an important issue for these people. Therapeutic options for the diabetic worker have been developed, and currently include various insulins, insulin sensitizers and secretagogues, incretin mimetics and enhancers, and alpha glucosidase inhibitors. Hypoglycemia and hypoglycaemic unawareness are important and unwanted treatment side effects. The risk they pose with respect to cognitive impairment can have safety implications. The understanding of the therapeutic options in the management of diabetic workers, blood glucose awareness training, and self-monitoring blood glucose will help to mitigate this risk. Employment decisions must also take into account the extent to which the jobs performed by the worker are safety sensitive. A risk assessment matrix, based on the extent to which a job is considered safety sensitive and based on the severity of the hypoglycaemia, may assist in determining one's fitness to work. Support at the workplace, such as a provision of healthy food options and arrangements for affected workers will be helpful for such workers. Arrangements include permission to carry and consume emergency sugar, flexible meal times, selfmonitoring blood glucose when required, storage/disposal facilities for medicine such as insulin and needles, time off for medical appointments, and structured self-help programs.

• Advances in concrete construction
• /
• 제16권1호
• /
• pp.35-57
• /
• 2023

Majority of the plastic produced each year is being disposed in land after single-use, which becomes waste and takes up a lot of storage space. Therefore, there is an urgent need to find alternative solutions instead of disposal. Recycling and reusing the PET plastic waste as aggregate replacement and fiber in concrete production can be one of the eco- friendly methods as there is a great demand for concrete around the world, especially in developing countries by raising human awareness of the environment, the economy, and Carbon dioxide (CO2) emissions. Self-compacting concrete (SCC) is a key development in concrete technology that offers a number of attractive features over traditional concrete applications. Recently, in order to improve its durability and prevent such plastics from directly contacting the environment, various kinds of plastics have been added. This review article summarizes the latest evident on the performance of SCC containing recycled PET as eco-friendly aggregates and fiber. Moreover, it highlights the influence of substitution content, shape, length, and size on the fresh and properties of SCC incorporating PET plastic. Based on the findings of the articles that were reviewed for this study, it is observed that SCC made of PET plastic (PETSCC) can be employed in construction era owing to its acceptable mechanical and fresh properties. On the other hand, it is concluded that owing to the lightweight nature of plastic aggregate, Reusing PET waste in the construction application is an effective approach to reduces the earthquake risk of a building.

• 한국방사성폐기물학회:학술대회논문집
• /
• 한국방사성폐기물학회 2004년도 학술논문집
• /
• pp.72-80
• /
• 2004

국내의 가동 중지된 우라늄 변환시설의 해체 시 다량의 우라늄으로 오염되어 있는 금속성 폐기물의 재활용 또는 자체처분을 위한 제염기술로 중성염 전해액을 사용하는 전해제염 공정의 적용성을 평가하기 위하여 우라늄 변환시설 내부설비의 주 구성 재료인 SUS-304 및 Inconel-600에 대한 전기화학적 용해거동 연구를 수행하였다. 이를 위하여 중성염 전해질의 형태, 전해질의 농도, 전류밀도, 처리시간과 같은 전해제염 조건들이 금속 재료의 용해에 미치는 영향을 평가하였다. 모의 시편을 사용한 비방사성 전해용해 실험 결과를 근거로 실제 우라늄 변환시설로부터 인출한 $UO_2$, AUC (ammonium uranyl carbonate) 및 ADU (ammonium diuranate) 오염시편에 대해 $Na_2SO_4$및 $NaNO_3$ 중성염 용액에서 전해 제염실험을 수행하였으며, 오염물의 종류 및 오염 준위의 대소와는 관계없이 모든 시편에 대하여 10분 이내의 짧은 시간 내에 자체처분 기준치 이하로 $\beta$ 방사능 준위를 감소시킴으로써 본 중성염 전해제염이 매우 성공적임을 확인하였다.

• 한국지반환경공학회 논문집
• /
• 제6권2호
• /
• pp.31-38
• /
• 2005

유동성 재료는 자기수평능력을 갖고 있으며, 액체와 같은 물질로 최대단위중량의 95~100 %의 자기 다짐율을 발휘할수 있다. 유동성 재료는 노동력이 적게 들고, 시공속도를 높일수 있으며, 접근이 어려운 장소에도 적용이 가능하면서도 재굴착이 용이한 장점이 있다. 따라서 각종 트렌치, 굴착작업, 지중구조물, 오수 및 유틸리티 관과 지중의 공동충전 등에 이용된다. 본 연구의 목적은 고함수비의 점성토와 폐스티로폼 입자, 안정재 등으로 구성된 유동성 재료의 공학적 특성을 평가하는 것이다. 이를 위하여 일축압축실험, 유동성 시험 및 모형충전성 실험을 실시하였으며 폐기물을 활용한 혼합토는 안정재의 양을 $1.0(kN/m^3){\sim}1.2(kN/m^3)$이상을 사용하면 유동성재료로서 사용가능한 것으로 나타났다.

• 기술사
• /
• 제15권1호
• /
• pp.46-50
• /
• 1982

Following rapid industrial development and urbanization in Korea, there is a need for the Government to implement effective control of pollution and to undertake specific schemes in areas where pollution of the environment is severe. In response to this need, Government of Korea prepare Han River Basin Environmental Master Plan Project for water, air, solid waste to cover environmental protection of the Han River Basin. The Project area is approximately 27,000 sq. Km extending over Seoul, Kyunggi, Kwangwon, Chungbuk Province. The total population of Master Plan Project area is approximately 11.6 million, or one-third of the total population of Korea. There are about 8,000 industries, including those located in 16 industrial complexes, in the project area. The scope of work and terms of reference are the following: (1) A Summary of existing land use and forecasts for changes in land use by the year 2,000. (2) Emission inventories for air, waste water, and solid wastes. (3) Forecasts of future population growth patterns and pollution loadings. (4) Identification of specific projects needs to reduce pollution levels and satisfy the environmental quality standards. (5) A Program of enforcement to include (i) self monitoring, and (ii) governmental inspections and surveillance. (6) A program for quality improvement and quality assurance of environmental measurements. (7) Reports summarizing all data collected analyzed during the study. (8) Conceptual design and feasibility studies, including cost estimates, for needed pollution control projects. (9) A financial plan for future detailed design and construction of public facilities, for financial incentives to industry, and for user charges for industrial use of public treatment of disposal works.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
• /
• pp.335-340
• /
• 2002

By the recently, Environmental pollution is serious by the highly economic growth and expansion of lively country basic industry. Especially, in case of industrial waste and life waste leaped into a pollution source. Also, research for processing of waste and recycling countermeasure is a pressing question on national dimension because it is prohibited an ocean disposal and reclamation. In this study, it looked for fracture characteristic value of recycling a coal ash to decrease environmental pollution by picky and exhaustion of natural resources and to reduce self-weight to prepare for a tall building and earthquake. So a coal ash examined to be possible to do as construction material. It achieved compressive strength test and three points bending test with initial notch depth rate and age for variables to show a basic research data. From the basis of the three points bending test, the fracture parameters - notch sensitivity, fracture energy, initial compliance were experimentally proposed. From the results of the compressive strength test, the elastic modulus was experimentally proposed. Also on the basis of the three points bending test, the fracture parameters - notch sensitivity, fracture energy, initial compliance were experimentally proposed. The results that the strength and fracture energy value are lower than concrete or mortar is described in this paper. Also, it shows that the deflection at fracture decreases as the age increases and the notch sensitivity decrease. However, it is judged to be available to construction material if research is continuously gone forward.

• Computers and Concrete
• /
• 제25권1호
• /
• pp.83-94
• /
• 2020

The use of fly ash in modern-day concrete technology aiming sustainable constructions is on rapid rise. Fly ash, a spinoff from coal calcined thermal power plants with pozzolanic properties is used for cement replacement in concrete. Fly ash concrete is cost effective, which modifies and improves the fresh and hardened properties of concrete and additionally addresses the disposal and storage issues of fly ash. Soft computing techniques have gained attention in the civil engineering field which addresses the drawbacks of classical experimental and computational methods of determining the concrete compressive strength with varying percentages of fly ash. In this study, models based on soft computing techniques employed for the prediction of the compressive strengths of fly ash concrete are collected from literature. They are classified in a categorical way of concrete strengths such as control concrete, high strength concrete, high performance concrete, self-compacting concrete, and other concretes pertaining to the soft computing techniques usage. The performance of models in terms of statistical measures such as mean square error, root mean square error, coefficient of correlation, etc. has shown that soft computing techniques have potential applications for predicting the fly ash concrete compressive strengths.