• Geomechanics and Engineering
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• v.34 no.4
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• pp.425-435
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• 2023

Granite and marble are widely produced and utilized in the construction industry, resulting in significant waste production. It is essential to manage this waste appropriately and repurpose it in recycling processes to ensure sustainability. The utilization of waste materials such as marble and granite waste (MGW) has become increasingly important in geotechnical engineering to improve the physical and mechanical properties of weak soils. This study investigated the applicability of utilizing MGW and cement (C)-MGW mixtures to improve clayey soil. A series of model plate loading tests were carried out in a specialized circular test tank to assess the influence of MGW and C-MGW mixing ratios on clayey soil samples. The samples were prepared by blending MGW and C-MGW in predetermined proportions. It is found that the bearing capacity of clay soil increased by approximately 71% when using MGW and C additives. Moreover, the consolidated settlement values of the clay soil decreased up to 6 times compared to the additive-free case.

• Tunnel and Underground Space
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• v.17 no.1 s.66
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• pp.32-42
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• 2007

Severe damage can occur around deposition holes due to complex interaction of thermo-hydro-mechanical (THM) loading during the long term operation of high level radioactive waste repository. Many candidate sites for repository are located in crystalline rock mass, therefore mechanism of damage follows the form of brittle fracture and failure. This paper briefly introduces major outcomes from 15 years international collaborative project, DECOVALEX, and presents major study results for current ongoing benchmark test study from DECOVALEX-THMC, to evaluate the effect of THM loading to rock mass in excavation damaged zone (EDZ) near deposition holes. Through benchmark test model by simplifying THM loading to boundary loading obtained numerical results are compared, and discrete fracture interaction after up to 1 million years operation is discussed.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.4
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• pp.537-548
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• 2020

Currently, radioactive waste for disposal has been restricted to low and intermediate level radioactive waste generated during operation of nuclear power plants, and these radioactive wastes were managed and disposed of the 200 L and 320 L of steel drums. However, it is expected that it will be difficult to manage a large amount of decommissioning waste of the Kori unit 1 with the existing drums and transportation containers. Accordingly, the KORAD is currently developing various and large-sized containers for packaging, transportation, and disposal of decommissioning waste. In this study, the radiation exposure doses of workers and the public were evaluated using RADTRAN computational analysis code in case of the domestic on-road transportation of new package and transportation containers under development. The results were compared with the domestic annual dose limit. In addition, the sensitivity of the expected exposure dose according to the change in the leakage rate of radionuclides in the waste packaging was evaluated. As a result of the evaluation, it was confirmed that the exposure dose under normal and accident condition was less than the domestic annual exposure dose limit. However, in the case of a number of loading and unloading operations, working systems should be prepared to reduce the exposure of workers.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.2
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• pp.107-114
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• 2024

Objectives: This study was performed to evaluate the musculoskeletal symptoms of workers treating electronics industry waste at a recycling sorting plant by case survey. Methods: The musculoskeletal symptoms were investigated by conducting a survey targeting workers treating waste from the electronics industry. Through utilizing the ergonomic evaluation techniques such as RULA, REBA, and OWAS, the four tasks were divided into three detailed processes (sorting, movement, loading) and the work of workers was evaluated for a total of 12 processes. Results: As a result of the questionnaire survey on musculoskeletal symptom, 40% of workers answered that they had musculoskeletal disease symptoms, and the symptom sites were hands(30%), legs(20%), arms(10%), and shoulders(5%). Based on the results obtained from analysis through ergonomic evaluation techniques such as RULA, REBA, and OWAS, 75% of them were found to need improvement or follow-up immediately or immediately after the second stage or higher. As compared to REBA and OWAS, the RULA, which evaluates the upper limb in detail, has a higher score, and in the process of sorting and loading relatively light wastes such as paper and plastic, the waist is raised by repeating the work of bowing and stretching. Conclusions: The heavy wastes such as 200L drums were evaluated as having a low load on the elbows and wrists because body action was relatively lower than moving paper and plastic. In addition, the overall load score was evaluated lower in the moving work compared to the sorting or loading process.

• Journal of Environmental Science International
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• v.15 no.10
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• pp.975-982
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• 2006

This study has been conducted to optimum operating conditions for effective acid fermentation according to OLR(organic loading rate) in the mesophilic and thermophilic acid fermentation process. The results are summarized as follows. In order to obtain reasonable acid fermentation efficiency in performing acid fermentation of food wastes in thermophilic condition, organic loading rate was required below 20 gVS/L.d. As $SCOD_{Cr}/TKN,\;SCOD_{Cr}/T-P$ of thermophilic acid fermented food wastes In organic loading rate 20 gVS/L.d were 18.9, 73.4 respectively, it was possible to utilize as external carbon source for denitrification in sewage treatment plant after solid-liquid separation as well as co-digestion of fermented food wastes and sewage sludge.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1012-1023
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• 2008

This paper estimates the long-term settlement of In-cheon unsanitary solid waste landfills. which is 20 years old. The unsanitary solid waste landfills was subjected to pre-loading system over a period of 1 year, and the settlement for 300 landfill monitors provided measured data. This landfill contain relatively small amount of organic component, therefore the initial stage of settlement was very small. The existing settlement models are examineed to compare with the observed behavior of this site and, also to estimate long-term settlement. The Hyperbolic, Bjarngard & Edgers, and Power Creep Law models showed good agreement well with the measured settlement of the In-cheon unsanitary solid waste landfills.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.1-6
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• 2017

Modern society has been experiencing by population growth and urbanization that bring, a change of eating habits which has occurred a various types of waste in a large amount. Even though these wastes are required an immediate treatment with difficulties unsanitary handling and existing waste treatment method are by incineration, fermentation, drying and etc. however a bad smell occurs after the treatment that need's a lot of energy in processing organic wastes with high moisture contents and wasteful and inefficient problem. The strength assessment of the organic waste agitating vessel is required in terms of safety due to the differences of loading on the shaft that was treated by agitating the mixture of food waste. The damage of agitating axis is depended on steam pressure, temperature condition and the force moment that exerted by the food waste. Thus the strength assessment and stability evaluation are very important, especially to handle a hard waste. In this study the rotation capacity of agitation is about 5 tons considering general structural rolled steel pressure vessel strength and steam pressure. The purpose is to estimate the safety and strength evaluation for a agitator axis and impellers according to the rotating angle of the axis under the condition of the 3.2 ton capacity reactor.

• Composites Research
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• v.26 no.4
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• pp.213-217
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• 2013

The focus in the present work is to study the agro-waste corn husk bio-filler as reinforcement for polypropylene. These materials have been created by extrusion and injection molding. The effect of filler content by 10, 20, 30 and 40 wt. % and mesh sizes of 50~100, 100 and 300 on the mechanical properties was studied. For the un-notched specimens, the results of flexural strength showed a declining trend with increase the filler loading and the results of impact strength showed an increasing trend with increase the mesh size. In contrast, enhanced flexural modulus was observed with increasing filler loading and size.

• Journal of Wetlands Research
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• v.4 no.1
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• pp.87-95
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• 2002

The objective of this study is to treat contaminated stream by using a UFBR(upflow fixed biofilm reactor) packed with waste-concrete media. This system was tested from June 1999 to January 2000. Over $20.0^{\circ}C$, $COD_{cr}$ removal efficiency did not affected with organic loading rate while, $COD_{cr}$ removal efficiency decreased about 7% with decrease of temperature from $27.0^{\circ}C$ to $8.7^{\circ}C$. Under $16^{\circ}C$, TKN removal efficiency was affected with TKN loading rate. The proposed model apply to mass balance equation of fixed biofilm reactor for predicting effluent was well satisfied with measured value($R^2=0.94$).

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2017.05a
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• pp.153-154
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• 2017

The thermal analysis of transportation and storage cask for SNF was conducted during short term loading operations for forced gas drying condition. The fuel cladding temperature in 6 regions of SNF in the cask during the short term loading operations for forced gas drying condition is shown in the Fig. 3. The thermal analysis results of calculated maximum cladding temperature in each process demonstrate that operating scenario of TFD in detailed design maintain well below the temperature limits of $400^{\circ}C$.