• Journal of the Korean Geotechnical Society
• /
• v.36 no.10
• /
• pp.33-39
• /
• 2020

A geological repository has been considered as an option for the disposal of high-level radioactive waste (HLW). The HLW is disposed in a host rock at a depth of 500~1,000 meters below the ground surface based on the concept of engineered barrier system (EBS). The EBS is composed of a disposal canister, buffer material, backfill material, and gap-filling material. The compacted bentonite buffer is very important since it can restrain the release of radionuclide and protect the canister from the inflow of ground water. The saturation of the buffer decreases because high temperature in a disposal canister is released into the surrounding buffer material, but saturation of the buffer increases because of the inflow of ground water. The unsaturated properties of the buffer are critical input parameters for the entire safety assessment of the engineered barrier system. In Korea, Gyeongju bentonite can be considered as a candidate buffer material, but there are few test results of the unsaturated properties considering temperature variation. Therefore, this paper conducted experiment of soil-water characteristic curve for the Gyeongju compacted bentonite considering temperature variation under a constant water content condition. The relative error showed approximately 2% between test results and modified van-Genuchten model values.

• Korean Journal of Clinical Pharmacy
• /
• v.17 no.1
• /
• pp.1-5
• /
• 2007

A computerized chemotherapy order system (CCOS) was developed to improve the accuracy and efficiency of prescriptions for pharmacy medication scheduling at a teaching hospital, Asan Medical Center, Seoul, Korea. We evaluated the system by comparing prescriptions before and after the implementation of the system and by analyzing the effects of the system on dosing accuracy (only against 5-FU), prescription change, overdoses above maximum limit and medication disposal in non computerized program group (control group) and CCOS group. In terms of dosing accuracy, prescription error rate (%) was significantly decreased in CCOS groups compared with the control group. The rate of prescription changes was also significantly decreased in CCOS groups. Regarding overdoses above maximum limit, we found that there was no prescription order exceeding the dosage limit in CCOS groups in contrast to significant overdoses in control group. In terms of medication disposal, there was no significant difference between 2 groups. We suggest that the computerized chemotherapy order system for chemotherapy may bean important and useful tool for minimizing prescribing errors in the hospitals.

• The Korean Journal of Archival Studies
• /
• no.6
• /
• pp.3-40
• /
• 2002

Appraisal is a basic archival function that analyzes values of records and determines the eventual disposal of records based upon their archival values. In Korea, this appraisal concept introduces in earnest through Public Records and Archives Act(PRA, 공공기관의 기록물관리에관한법률) with which Korean record management systems settle inflexibly. In theoreical and methodological area, therefore, it is necessary to analyze appraisal system in this Act with it in archival science. In PRA Act, appraisal system is founded on the Tables of Transaction for Records Scheduling(TRS, 기록물분류기준표) through which disposal activities of all records are definited in a concrete form. In this system, selection of archival materials which has been recognized as a important function of record center is carried out by record creators and archival institutions; Primary value between semi-currenty and non-currenty are reflected at the same time. In view of values, this appraisal system intends to separate reasonably consideration for continuing utility of achives from current use of records throughout agencies duration. Ultimately, appraisal based upon TRS makes up not separated management course but organic courses reflecting the Continuum of Care. Of course, this appraisal system makes up the deficiency partially. TRS regarded as 'mainboard' of current appraisal system will have to be enacted elaborately. And appraisal strategies of electronic records must set up in detail in PRA Act and TRS. Lastly, arrangement and description concepts immanent in TRS will have to supplement in archival institutions.

• Korean Journal of Construction Engineering and Management
• /
• v.9 no.1
• /
• pp.77-86
• /
• 2008

On account of increasing interest of substantiality in these day, it is needed to make an effort to establish an environmentally sustainable production system for the construction works. Although practical affairs and researches are in progress to reduce and recycle construction wastes, as a result of a research, there are still obstructive factors on waste reduction and recycling which they don't interact efficiently between waste disposal process of the construction area and waste disposal company. As a plan to revitalize reduction and recycling of construction wastes, this research focuses on finding obstructive factors and giving solutions to reduce and recycle construction wastes which comes from construction process and construction industries. To meet the needs of the research, firstly relatively significant construction wastes (concrete, soil, brick, block, asphalt, plastic, lumber) were identified. On site level interviews with management of disposal companies and construction sites were conducted as well, focusing on typical waste disposal process. Throughout this interviews, obstructive factors were conducted. A result of the research, the authors suggest an improved approach on disposal and recycling for construction waste by prioritizing the identified factors and ranking the importance level of each factor. And, by identifying factors obstructing reduction and recycle of construction wastes, this research suggests improved disposal process of construction waste.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.12 no.4
• /
• pp.315-334
• /
• 2014

Wolsong Low- and Intermediate-level radioactive waste (LILW) disposal center has two different types of disposal facilities and interacts with the neighboring Wolsong nuclear power plant. These situations impose a high level of complexity which requires in-depth understanding of phenomena in the safety assessment of the disposal facility. In this context, multidimensional radionuclide transport model and hydraulic performance assessment model should be developed to identify more realistic performance of the complex system and reduce unnecessary conservatism in the conventional performance assessment models developed for the $1^{st}$ stage underground disposal. In addition, the advanced performance assessment model is required to calculate many cases to treat uncertainties or study parameter importance. To fulfill the requirements, this study introduces the development of two-dimensional integrated near-field performance assessment model combining near-field hydraulic performance assessment model and radionuclide transport model for the $2^{nd}$ stage near-surface disposal. The hydraulic and radionuclide transport behaviors were evaluated by PORFLOW and GoldSim. GoldSim radionuclide transport model was verified through benchmark calculations with PORFLOW radionuclide transport model. GoldSim model was shown to be computationally efficient and provided the better understanding of the radionuclide transport behavior than conventional model.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.16 no.2
• /
• pp.261-270
• /
• 2018

In this study, to replace the 'J-slot joint', a joint device between a disposal canister and an emplacement jig in Deep Borehole Disposal process, a novel joint device was designed and tested. The novel joint device was composed of a wedge on top of a disposal canister and a hook box at the end of a winch system. The designed joint device had merits in that it can recombine an emplaced canister freely without the replacement of the joint component. Moreover, it can be applied to various emplacement jigs such as drill pipes, wire-lines, and coiled tubing. To demonstrate the designed joint device, the joint device (${\Phi}110mm$, H 148 mm), a twin canister string (${\Phi}140mm$, H 1,105 mm), and a water tube (${\Phi}150mm$, H 1,500 mm) as a borehole model were manufactured at 1/3 scale. As deployment muds, Na-type bentonite (MX-80) and Ca-type (GJ II) bentonite muds were prepared at solid contents of 7wt% and 28wt%, respectively. The manufactured joint device showed good performance in pure water and viscous muds, with an operation speed of $10m{\cdot}min^{-1}$. It was concluded that the newly developed joint device can be used for the emplacement and retrieval of a deep disposal canister, below 3~5 km, in the future.

• Journal of Environmental Impact Assessment
• /
• v.28 no.3
• /
• pp.312-331
• /
• 2019

An offshore waste disposal facility refers to a landfill site for final landfilling of stabilized inorganic solid waste such as land and marine waste incineration materials, and the aim of such a facility is to solve the problem of insufficient waste disposal space on land and create and develop environmentally friendly marine spaces. The purpose of this study is to prepare guidelines for the construction of offshore waste disposal facilities, which reflect the need and importance of paying sufficient heed to environmental considerations from the initial stage of the project, in order to investigate, predict, and assess how such guidelines will affect the marine environment in relation to the construction of offshore waste disposal facilities, with the goal of minimizing the impact on and damage to the environment. For the purpose of this research, guidelines focusing on the construction of offshore waste disposal facilities were derived through an analysis of domestic cases and similar foreign cases and an assessment of their level of compliance with existing EIA guidelines through the operation of a discussion forum. In order to review the EIA report on similar cases in Korea, 17 EIA documents (2005~2016) for dredged soil dumping areas and ash ponds of thermal power plants were analyzed to investigate the status of marine organisms, marine physics, marine water quality, and marine sediment and to understand what types of problems can occur and what improvement measures can be taken. The purpose of these guidelines were to minimize damage to the marine environment by promoting EIA protocols in accordance with scientific and systematic procedures, to reduce the consultation period related to projects, to resolve social conflicts, and to reduce economic costs.

• Journal of the Korean Society of Systems Engineering
• /
• v.17 no.1
• /
• pp.65-75
• /
• 2021

When the decommissioning of South Korea nuclear power plants is promoted in earnest with the permanent shutdown of Kori Unit 1 in 2017, a large amount of various types of radioactive waste will be generated. For minimal generation and safe management of decommissioning waste, the waste should be made by appropriate classification of the dismantling waste characteristics in accordance with physical, chemical and radiological characteristics to meet the acceptance criteria of disposal facilities. Replacing the preliminary inspection at the site for the compliance of the waste acceptance criteria (WAC) of medium and low-level radioactive waste with the generator's own radioactive waste certification program (WCP), from the perspective of disposal, the optimization of waste management at the national level contributes to the efficient availability of disposal, such as the processing of non-conforming radioactive wastes at the site. To this end, it is important to evaluate radioactivity in each system and area such as nuclear reactors before decommissioning is carried out in earnest, and the prior removal of harmful wastes is important. From waste collection to waste disposal, decommissioning waste should be managed at each stage in consideration of the acceptance criteria of disposal facilities to minimize the generation of non-conforming waste.

• Journal of the Korean Geotechnical Society
• /
• v.34 no.1
• /
• pp.17-24
• /
• 2018

A buffer in a geological disposal system minimizes groundwater inflow from the surrounding rock and protects the disposed high-level waste (HLW) against any mechanical impact. As decay heat of a spent fuel causes temperature variation in the buffer that affects the mechanical performance of the system, an accurate estimation of the temperature variation is substantial. The temperature variation is affected by thermal and material properties of the system such as thermal conductivity, density and specific heat capacity of the buffer, and thus these factors should be properly included in the design of the system. In particular, as the thermal properties are variable depending on the density and water content of the buffer, consideration of the effects should be included in the analysis. Hence, in this study, a numerical model based on finite element method (FEM) which is able to consider the change of density and water content of the buffer was established. In addition, using the numerical model, a parametric study was conducted to investigate the effect of each thermal property on the temperature variation of the buffer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.664-665
• /
• 2016

This paper proposes an identification system based on QR (Quick Response) code for production and disposal information of Internet of Things (IoT) devices. Three thousands and five hundreds of electronic devices have replaced and discarded in South Korea in a year, and twenty millions to fifty millions tons of e-wastes have happened throughout the world every year. According to Gartner, market research institution, the number of IoT devices will increase from 2.3 billions in 2013 to 30 billions in 2020, however, the regulations and systems which take into account environment were not prepared. The identification systems for reflecting information of devices, which are produced or discarded, are required to resolve the problem. The proposed identification system based on QR code can store much more massive data such as the producer, product's model, serial number, recycling rate, recovering rate, recyclability rate, recoverability rate than RFID (Radio-Frequency Identification). Also, users can immediately recognize production and disposal information by a QR code application in a smartphone.