• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.20 no.2
• /
• pp.243-253
• /
• 2022

Spent filters with a high radiation dose rate of 2 mSv·hr^-1 or more are not easily managed. So far, the Korean policy for spent filter disposal is to store them temporarily at nuclear power plants until the waste filters can be easily managed. Nuclear power plant decommissioning in Korea is starting with Kori unit 1. Volume reduction of waste generated during decommissioning can reduce the cost and optimize the space usage at disposal site. Therefore, efficient volume reduction is a very important factor during the decommissioning process. A conceptual method, based on the experiences of developing 200 and 800 ton compactors at Orion EnC, has been developed considering worker exposure with the followings a crusher (upgrade of compaction efficiency), an automatic dose measuring system with a NaI(Tl) detector, a shield box, an inner drum to prepare for easy handling of drums and packaging, a 30 ton compactor, and an automatic robot system. This system achieves a volume reduction ratio of up to 85.7%; hence, the system can reduce the disposal cost and waste volume. It can be applied to other types of wastes that are not easily managed due to high dose rates and remote control operation necessity.

• Korean Journal of Organic Agriculture
• /
• v.28 no.4
• /
• pp.535-553
• /
• 2020

In this study, the characteristics of the waste sector CDM project were analyzed through cluster analysis of the waste sector CDM project and the analysis of the CDM investment cost in waste sector using CDM project data registered with UNFCCC since 2008 when EU ETS phase 2 began. As of September 2020, 772 cases of CDM projects in waste disposal and disposal are registered. Biogas technology is the largest, followed by livestock manure processing and biomass production technology. The results of the cluster analysis are summarized as follows: First, on average, projects utilizing AWMS technology are small in size and relatively low in investment costs. This is judged to be relatively low investment costs due to previously attracted foreign investment capital. Second, the average investment cost of CDM projects considered along with waste (No.13), the energy industry (No.1) and agriculture (No.15) was higher than those involving only waste. The analysis of the factors determining the investment cost of the waste sector CDM project showed that, as with cluster analysis, the AWMS technology, which is a livestock manure treatment technology, was lower in the investment cost than those that use other technologies. As a result of multiple regression analysis, the investment cost of the CDM project was analyzed lower in the order of biomass, AWMS, LFG and biogas. Also, the higher the investment cost for CDM projects linked to waste, energy and agriculture, and the better the investment environment, the higher the investment cost. Although no statistical feasibility was obtained, the larger the annual emission reduction, the lower the CDM investment cost.

• Hwankyungkyoyuk
• /
• v.11 no.2
• /
• pp.144-155
• /
• 1998

This research aims to perceive the present state of science experimental education practiced in middle school and also to improve the laboratorial environment. Accordingly, this study surveyed 297 middle school science teachers in Seoul to examine the risks and accidents occurred during lab sessions, the conditions of chemical waste disposal, and whether or not teacher's manual clearly states cautions on toxic chemicals. About 70%(69.6%) of science teachers were highly concerned about risks and toxicity of chemicals used in classes, 59.9% experienced actual accidents, and 83.2% were anxiety of incidents caused by chemicals. Besides, 55.2% of science teachers answered that they have little knowledge about caring noxious chemicals used in lab sessions. So it turns out that they need more specific education on handling toxic chemicals. More than one third(36.7%) answered that they disposed of chemical waste water without any special care or kept it in the lab after experiments. The number of chemicals as well used in middle school curriculum is increasing as grades gets higher toxic chemicals. However, there are few teachers' manual covering how to handle noxious chemicals. Therefore, in middle school curriculum the number of poisonous chemicals should be minimized as much as possible, and in case the toxic chemicals have to be used, teacher's guide book should state precautions on handling chemicals in detail. Also government should make it obligatory on schools to instate ventilator for chemical waste, or to transport the waste to proper disposal systems.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.18 no.2_spc
• /
• pp.317-325
• /
• 2020

The Korea Radioactive Waste Agency plans to expand the storage capacity of radioactive waste by constructing a radioactive waste inspecting building to solve the problem of the lack of inspection space and drum-handling space in the radioactive waste receipt and storage building for the first-stage disposal facility. In this study, the exposure doses of radiation workers that handle new disposal containers for decommissioning waste in the storage areas of the radioactive waste inspecting building were calculated using the Monte Carlo N-particle transport code. The annual collective dose was calculated as a total of 84.8 man-mSv for 304 new disposal containers and an estimated annual 306 working hours for the radiation work. When the 304 new disposal containers (small/medium type) were stored in the storage areas, it was found that 25 radiation workers should be involved in acceptance/disposal inspection, and the estimated exposure dose per worker was calculated as an average annual value of 3.39 mSv. When the radiation workers handle the small containers in high-radiation dose areas, the small containers should be shielded further by increasing the concrete liner thickness to improve the work efficiency and radiation safety of the radiation workers. The results of this study will be useful in establishing the optimal radiation working conditions for radiation workers using the source term and characteristics of decommissioning waste based on actual measurements.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.4 no.3
• /
• pp.301-309
• /
• 2006

KDC-1 canister for PWR spent fuels which will be used for the Korean Reference Disposal System was developed. The structural analysis of the canister was carried out as a part of the safety analysis. Two conditions, disposal condition and handling condition, were considered for the structural analysis. Three kinds of load cases, normal, abnormal and rock movement, were considered for the disposal condition. The results of the calculation showed that the safety factors from the structural analysis were greater than the design requirements. Two accident scenarios, gripper failure accident and canister drop accident, were analyzed for the handling condition. According to the gripper failure scenario analysis, the handling machine with grippers could be used even in the cases that one or two grippers failed. The maximum von Mises stress from the canister drop accident scenario was 0.762 MPa, which was negligible compared with the yield stress of nodular cast iron. The proposed KDC-1 canister for PWR spent fuels proves to be safe under the repository condition that is based upon the Korean reference disposal system according to the structural analysis for disposal condition and handling condition.

• Journal of Environmental Science International
• /
• v.13 no.3
• /
• pp.301-311
• /
• 2004

The purpose of this study was to examine teachers’ awareness of chemical waste produced in elementary school laboratory experimentation and how this awareness relates to collection and disposal of chemical waste. More specifically, the study looked at the correlation between the handling of chemical waste and factors such as years of teachers’ educational career, class size and amount of waste produced. The target population were 250 elementary school teachers in Gyeongnam area and 237 subjects were responded. Among the 237 responses, 37 cases that did not complete the questionnaire were eliminated. Therefore, 200 responses were analyzed in this study. The survey questionnaire consisted of 15 questions. The categories of the questionnaire were their skills of management and treatment of the chemical waste. The data collected were analyzed by SPSS 10.0, and the relations among variables such as class sizes and years of teaching experience were also analyzed by $x^2-test.$ The results in this study were as follows: First, there were no significant differences between the years of teaching and class sizes in the training experience of chemical waste disposal. Second, there was a significant difference between the science laboratory size and class sizes in the laboratory actual condition. In addition, in the relations between the number of times of experimentation and the years of teaching experience, there was a significant difference. Third, in terms of the discharge amount of chemical waste, there was a significant difference between the years of teaching and class sizes. Fourth, in the simple chemistry waste disposal process in the science laboratory, there also was a significant difference between the kinds of experimental equipments that used in the experimentation and the years of teaching. Based on this study, it was found that great amount of the chemical wastes produced in the science laboratory dumped into the drain and the treatment process of chemical waste was also inattentive. Even the importance of environmental education is emphasized in the elementary education, the basic problems occurred in the science laboratory is disregarded. Therefore, not only students but teachers have to pay attention to the disposal process of chemical waste in the laboratory in order to prevent environment pollution. Furthermore, the efforts of preventing environment pollution are needed such as opening the teacher training course about environment education, minimal use of chemicals, treatment of chemical waste, and so forth.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.21 no.2
• /
• pp.255-269
• /
• 2023

Compared to operational wastes, nuclear power plant (NPP) decommissioning wastes are generated in larger quantities within a short time and include diverse types with a wider range of radiation characteristics. Currently used 200 L drums and IP-2 type transport containers are inefficient and restrictive in packaging and transporting decommissioning wastes. Therefore, new packaging and transport containers with greater size, loading weight, and shielding performance have been developed. When transporting radioactive materials, radiological safety should be assessed by reflecting parameters such as the type and quantity of the package, transport route, and transport environment. Thus far, safety evaluations of radioactive waste transport have mainly targeted operational wastes, that have less radioactivity and a smaller amount per transport than decommissioning wastes. Therefore, in this study, the possible radiation effects during the transport from NPP to disposal facilities were evaluated to reflect the characteristics of the newly developed containers and decommissioning wastes. According to the evaluation results, the exposure dose to transport workers, handling workers, and the public was lower than the domestic regulatory limit. In addition, all exposure dose results were confirmed, through sensitivity analysis, to satisfy the evaluation criteria even under circumstances when radioactive materials were released 100% from the container.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1636-1639
• /
• 2005

The process equipment and remote handling for the deep geological disposal of high-level radioactive waste(HLW) should be checked prior to the operation in view of reliability and operability. In this study, the concept of virtual environment workcell is implemented to analyze and define the feasible disposal process instead of real mock-up, which is very expensive and time consuming. To do this, the parts of process equipment for the disposal and maintenance will be modeled in 3-D graphics, assembled, and kinematics will be assigned. Also, the virtual workcell for the encapsulation and disposal process of spent fuel will be implemented in the graphical environment, which is the same as the real environment. This virtual workcell will have the several functions for verification such as analyses for the equipment's work space, the collision detection, the path planning and graphic simulation of the processes etc. This graphic virtual workcell of the HLW disposal process can be effectively used in designing of the processes for the hot cell equipment and enhance the reliability of the spent fuel management.

• Nuclear Engineering and Technology
• /
• v.53 no.2
• /
• pp.549-561
• /
• 2021

Indonesia has policies and strategies for the management of radioactive waste and spent nuclear fuel that arises from the use of nuclear research and development facilities, including three research reactors, and the use of radioisotopes in medicine and industries. The Indonesian government has provided extensive facilities such as an independent regulatory organization (BAPETEN) and a centralized radioactive waste management organization (CRWT-BATAN). Further, the presence of regulations and several international conventions guarantee the protection of the public from all risks due to handling radioactive waste and spent nuclear fuel. However, the sustainability of radioactive waste management in the future faces various challenges, such as disposal issues related to not only to site selection but also financing of radioactive waste management. Likewise, the problem of transportation persists; as an archipelago country, Indonesia still struggles to manage the infrastructure required for the transport of radioactive materials. The waste from the production of the radioisotopes, especially from the production of 99Mo, requires special attention because BATAN has never handled it. Indonesia should also resolve the management of NORM from various activities. In Indonesia, the definition of radioactive waste does not include NORM. Therefore, the management of this waste needs revision and improvement on the regulations, infrastructure, and technology.

• Environmental Engineering Research
• /
• v.24 no.2
• /
• pp.220-237
• /
• 2019

Solid waste management (SWM) is one of the poorly rendered services in developing countries - limited resources, increasing population, rapid urbanization and application of outdated systems leads to inefficiency. Lack of proper planning and inadequate data regarding solid waste generation and collection compound the SWM problem. Decision makers need to formulate solutions that consider multiple goals and strategies. Given the large number of available options for SWM and the inter-relationships among these options, identifying SWM strategies that satisfy economic or environmental objectives is a complex task. The paper develops a mathematical model for a municipal Integrated SWM system, taking into account waste generation rates, composition, transportation modes, processing techniques, revenues from waste processing, simulating waste management as closely as possible. The constraints include those linking waste flows and mass balance, processing plants capacity, landfill capacity, transport vehicle capacity and number of trips. The linear programming model integrating different functional elements was solved by LINGO optimization software and various possible waste management options were considered during analysis. The model thus serves as decision support tool to evaluate various waste management alternatives and obtain the least-cost combination of technologies for handling, treatment and disposal of solid waste.