• Proceedings of the Korean Radioactive Waste Society Conference
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• 2006.11a
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• pp.203-204
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• 2006

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.137-144
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• 2005

Silica in primary system combines with an alkali grammatical particle metal and forms the zeolite layer which is hindering the heat transfer on the surface of the cladding. Zeolite layer becomes the cause of the damage in this way. The problems of the NPP's primary system have been issued steadily by EPRI. Through a series of experiments of the laboratory scale, we confirmed the applicability of NF membrane for silica removal, as silica rejection rate of NF membrane is about $60\;{\sim}\;70\%$ and boron rejection rate is about $10\;{\sim}\;20\%$. We accomplished a site experiment about four NF membranes manufactured by FilmTec and Osmonics Inc. In experiment using 400L of SFP water, when operation pressure is $10kg_{f}/cm^2$, we confirmed that the silica rejection rate of NF90-2540 manufactured by FilmTec Inc. is about $98\%$, boron rejection rate is about $43\%$. The silica rejection rate of NF270-2540 is about $38\%$, boron rejection rate is about $3.5\%$. Afterward, through additional experiments, such as long term characteristic experiments, we are going to design a optimum NF membrane system for silica removal.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.2 s.257
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• pp.116-124
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• 2007

An adsorption chiller is expected to have high energy-efficiency in utilizing the waste heat exhausted from a process. The objective of this paper is to investigate the performance of silica gel-water adsorption chiller from the cycle simulation and to provide a guideline for design of the adsorption chiller. The effect of cycle time, inlet temperature and water flow rate on the cooling capacity and COP is quantified during the cycle operation. It is found that the performance of adsorption chiller is more sensitive to the change of inlet water temperature rather than the water flow rate. It is concluded that the COP is 0.57 in the standard conditions(hot water $80^{\circ}C$, cooling water $30^{\circ}C$, chilled water inlet temperatures $14^{\circ}C$ and cycle time 420sec).

• Geomechanics and Engineering
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• v.30 no.6
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• pp.517-524
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• 2022

Every year, millions of waste tires are discarded across the world. Storage of waste tires presents many problems such as fire threats, epidemics, and non-economic factors. Furthermore, the disintegration process of waste tires is not economical or practical due to its time-consuming, and disposal requirements. In this study, half-section waste tires (HSWTs) were integrated with high-density polyethylene (HDPE) pipes under different relative density conditions. The main aim of the study was to reduce the deformation values of embedded HDPE pipes in sandy soil and to evaluate the soil-pipe interaction. In comprehensive laboratory tests, half-section waste tires were integrated in two different ways: in the middle of the pipeline and along the pipeline. Accordingly, it was concluded that the effectiveness of waste tires reduces the deformation and bending moment values in the critical regions of pipes. As a result of reinforcement in the mid-point of the pipe defined as the most critical region, 52% and 36% less deformation was observed in the crown and springlines of the pipe, respectively. In addition, the bending moment values for the same critical section were determined to be 40% less in the crown and 28% less in the springline regions of the pipe.

• Resources Recycling
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• v.11 no.5
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• pp.24-29
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• 2002

In this study, to improve the color of iron oxide from waste pickling acid at the cold rolling mill, the quality control technologies especially about color were investigated on the spray roaster and iron oxide powder. At the operation condition of the spray roaster, the charge amount of waste acid per hour, temperature, numbers of spray nozzle were investigated. At admixing process, titanium oxide, silica, goethite were tested. Color character of iron oxide can be improved by process control at spray roaster and by admixing process at a pigment factory Iron oxide from results of this study is enough to use as the colorant of concrete product.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.144-148
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• 2001

In this study, to improve the color of iron oxide from waste pickling acid at the cold rolling mill, quality control technologies to improve color were investigated. During operation of the spray roaster, the charge amount of waste acid per hour, temperature, and numbers of spray nozzles were investigated. At the admixing process, titanium oxide, silica, and goethite were tested. The color character of iron oxide can be improved by process control of the spray roaster and the admixing process at a pigment factory. Iron oxide from this study is appropriate for use as a colorant of a concrete product.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.4
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• pp.45-59
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• 2016

This study introduced wood waste into revegetation base materials for recovery of highway cut slope. The object of this study is to derive the mixing ratio of wood waste, kaoline and silica by conducting a test installation, monitoring, analysis and evaluation. The following items were investigated and analyzed each experimental zone to deduce the mixing ratio of wood waste, kaoline and silica on slope revegetation base materials: the physical and chemical properties of the vegetation base materials, soil-hardness, soil-humidity, collapse and eroded spots, established number of trees, existing species of grass and tree species, vegetation coverage ratio, pest status, and invasion of disturbance species. The revegetation method was evaluated in each experiment zone which had different mixing ratios. As a result, experiment zone C scored 47 points out of 60 as the best revegetation method. However, this result has been derived from just one construction and short-term monitoring. In order to derive the suitable and dependable mixing ratio, conducting an objective revegetation method evaluation and long-term experimenting and monitoring is required.

• Journal of Radiation Protection and Research
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• v.29 no.1
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• pp.1-8
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• 2004

Diphosil, a new version of the organic-inorganic composite resin developed by ANL has a structure of the chelating diphosphonic acid groups grafted to a silica support. To apply Diphosil for the treatment of liquid radioactive waste from nuclear power plants, the adsorption equilibrium and column experiments were carried out for the main radionuclides, $^{137}Cs\;and\;^{60}Co$, in the liquid radwaste stream. Through the adsorption equilibrium experiments, the removal efficiencies of $^{137}Cs\;and\;^{60}Co$, and the effects of non-radioactive ions on the removal efficiency have been measured in various conditions using radiotracers. The breakthrough curves for the tested tracers were obtained from the laboratory scale column tests using the simulated liquid radioactive waste. In addition, the removal capacity of Diphosil is compared with that of Amberlite IRN 77 resin, generally used in nuclear power plants.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4708-4714
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• 2022

The novelty in the present search, the Soda-Lime-Silica (SLS) glass waste to prepare free lead glass shielding was used in order to limit the accumulation of glass waste, which requires extensive time to decompose. This also saves on the consumption of pure SiO₂, which is a finite resource. Furthermore, the combining of BaO with Bi₂O₃ into a glass network leads to increased optical properties and improved attenuation. The UV-Visible Spectrophotometer was used to investigate the optical properties and the radiation shielding properties were reported for current glass samples utilizing the PhysX/PDS online software. The optical property results indicate that when BaO content increases in glass structure, the Urbach energy ΔE, and refractive index n increases while the energy optical band gap E_opt decreases. The result of the metallisation criteria (M) revealed that the present glass samples are nonmetallic (insulators). Furthermore, the radiation shielding parameter findings suggest that when BaO was increased in the glass structure, the linear attenuation coefficient and effective atomic number (Z_eff) rose. But the half-value layer HVL declined as the BaO concentration grew. According to the research, the glass samples are non-toxic, transparent to visible light, and efficient radiation shielding materials. The Ba5 sample is considered the best among all the samples due to its higher attenuation value and lower HVL and MFP values, which make it a suitable candidate as transparent glass shield shielding.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.812-818
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• 2024

The volume and toxicity of radioactive waste can be decreased by separating the components of high-level liquid waste according to their properties. An impregnated silica-based adsorbent was prepared in this study by combining N,N,N',N',N",N"-hexa-n-octylnitrilotriacetamide (HONTA) extractant, N',N'-di-n-hexyl-thiodiglycolamide (Crea) extractant, and macroporous silica polymer composite particles (SiO₂-P). The performance of platinum-group metals adsorption and separation on prepared (HONTA + Crea)/SiO₂-P adsorbent was then assessed together with that of co-existing metal ions by batch-adsorption and chromatographic separation studies. From the batch-adsorption experiment results, (HONTA + Crea)/SiO₂-P adsorbent showed high adsorption performance of Pd(II) owing to an affinity between Pd(II) and Crea extractant based on the Hard and Soft Acids and Bases theory. Additionally, significant adsorption performance was observed toward Zr(IV) and Mo(VI). Compared with studies using the Crea extractant, the high adsorption performance of Zr(IV) and Mo(VI) is attributed to the HONTA extractant. As revealed from the chromatographic experiment results, most of Pd(II) was recovered from the feed solution using 0.2 M thiourea in 0.1 M HNO₃. Additionally, the possibility of recovery of Zr(IV), Mo(VI), and Re(VII) was observed using the (HONTA + Crea)/SiO₂-P adsorbent.