• Journal of Integrative Natural Science
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• v.10 no.4
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• pp.225-231
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• 2017

Cryptand resins were synthesized by mixing 1-aza-18-crown-6 macrocyclic ligand with styrene divinylbenzene copolymer having 1%, 2%, 5%, and 10% crosslink by a substitution reaction. These synthetic resins were confirmed by chlorine content, elementary analysis, SEM, surface area, and IR-spectrum. As the results of the effects of pH, crosslink of synthetic resin, and dielectric constant of a solvent on uranium ion adsorption for resin adsorbent, the uranium ion showed high adsorption at pH 3 or over. Adsorption selectivity for the resin in methanol solvent was the order of uranium ($UO_2{^{2+}}$) > calcium ($Ca^{2+}$) > neodymium ($Nd^{3+}$) ion, adsorbability of the uranium ion was the crosslink in order of 1%, 2%, 5%, and 10% and it was increased with the lower dielectric constant.

• Toxicological Research
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• v.30 no.2
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• pp.117-120
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• 2014

Uranium is toxic and radioactive traces of it can be found in natural water and soils. High concentrations of it in biological systems cause genetic disorders and diseases. For the in vivo diagnosis, micro and nano range detection limits are required. Here, an electrochemical assay for trace toxic uranium was searched using stripping voltammetry. Renewable and simplified graphite pencils electrode (PE) was used in a three-electrode cell system. Seawater was used instead of an electrolyte solution. This setup can yield good results and the detection limit was attained to be at $10{\mu}gL^{-1}$. The developed skill can be applied to organic liver cell.

• Journal of the Korean Ceramic Society
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• v.37 no.9
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• pp.833-838
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• 2000

기존의 핵연료재료 습식처리 공정 대체를 위한 건식 처리 공정 기초 연구로서 산소 플라즈마 기체에 의한 금속우라늄과 이산화우라늄의 산화 연구를 수행하였다. 연구결과 산소 플라즈마를 사용할 경우 $UO_2$는 40$0^{\circ}C$에서 약 300% 정도, 50$0^{\circ}C$에서는 70% 정도의 산화율 증가가 일어났으며 금속우라늄의 경우에도 35$0^{\circ}C$에서 50% 정도의 증가를 확인할 수 있었다. 이들 산화율은 플라즈마 출력이 증가함에 따라 비례적으로 증가하였는데 이는 출력 증가에 따른 플라즈마내 산소 원자의 발생과 일치하여 이러한 산화율 증가 현상은 플라즈마내 산소 원자가 주도하는 것으로 드러났다. 이들 실험 결과는, 기존의 실험 결과와 길이, 시간에 따라 산화량이 선형적으로 증가하는 것으로 나타나 산소 플라즈마 산화 반응은 표면 반응이 주요 반응이라는 것이 밝혀졌다.

• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.284-292
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• 2015

A numerical calculation with the commercial computational fluid dynamics code CFX-14.0 was conducted for a test facility simulating the Canadian deuterium uranium moderator thermal-hydraulic. Two kinds of moderator thermal-hydraulic tests at Stern Laboratories Inc. were performed in the full geometric configuration of the Canadian deuterium uranium moderator circulating vessel, which is called a calandria tank, housing a matrix of horizontal rod bundles simulating calandria tubes. The first of these tests is the pressure drop measurement of a cross flow in the horizontal rod bundles. The other is the local temperature measurement on the cross section of the horizontal cylinder vessel simulating the calandria system. In the present study, the full geometric details of the calandria tank are incorporated in the grid generation of the computational domain to which the boundary conditions for each experiment are applied. The numerical solutions are reviewed and compared with the available test data.

• Nuclear Engineering and Technology
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• v.39 no.6
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• pp.731-736
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• 2007

Radioactive organic wastes containing acetone, alcohol, and particularly tributyl phosphate (TBP)/dodecane contaminated with uranium are extracted from the PUREX process and the decontamination of related equipment. An evaporation method that utilizes existing DU oxidation apparatuses and ventilation systems and a typical muffle furnace installed with an aspirating system are adopted. A separation method using phosphoric acid especially for the TBP/dodecane waste is also studied and evaluated. The results show that a simple evaporation process is utilizable for wastes containing acetone or alcohol with a lower boiling point. A modified muffle furnace is more appropriate to dispose directly of organic wastes having a higher boiling point, such as TBP/dodecane, without generating a condensed waste solution. It is recommended that, when the uranium concentration of TBP/dodecane waste is much higher than stipulated levels, separation technology should be applied to remove uranium from the mixture. Each type of solvent after separation can then be considered disposable below the regulatory limit in the modified furnace discussed in this study.

• Membrane and Water Treatment
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• v.3 no.4
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• pp.231-242
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• 2012

The performance of a nanofiltration membrane for treatment of a low-level radioactive liquid waste was investigated through static and dynamic tests. The liquid waste ("carbonated water") was obtained during conversion of $UF_6$ to $UO_2$. In the static tests membrane samples were immersed in the waste for 24, 48 or 72 h. The transport properties of the samples (hydraulic permeability, permeate flow, selectivity) were evaluated before and after immersion in the waste. In the dynamic tests the waste was permeated in a permeation flow front system under 0.5 MPa, to determine the selectivity of NF membranes to uranium. The surface layer of the membrane was characterized by zeta potential, field emission microscopy, atomic force spectroscopy and infrared spectroscopy. The static test showed that the pore size distribution of the selective layer was altered, but the membrane surface charge was not significantly changed. 99% of uranium was rejected after the dynamic tests.

• Journal of the Korean Chemical Society
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• v.5 no.1
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• pp.84-87
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• 1961

A polarographic method for rapid determination of Uranium in the presence of foreign ions was proposed. The method is based on the measurement of polarogram in the sulfuric acid as supporting electrolyte. In this medium Uranyl ions give well defined reduction waves, and half-wave potentials are -0.19V vs. S.C.E. as first wave, and uncertain volt. vs. S.C.E. as second wave in $2.4 N-H_2SO_4.$ The first wave has a linear relationship between the concentration of Uranyl ion and wave height. The author also studied a method for rapid determination of Uranium in Korean monazite sand without eliminating the foreign ions. The Korean monazite sands were analyzed by this method and satisfactory result were obtained.

• Journal of environmental and Sanitary engineering
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• v.23 no.2
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• pp.47-53
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• 2008

The ion exchange resins have been synthesized from chloromethyl styrene (dangerous matter) 1, 4-divinylbenzene(DVB) with 1%, 5%, and 15%-crosslinked and macrocyclic ligand of cryptand type by copolymerization method and the adsorption of uranium(VI), cobalt(II) and europium(III) ions have been investigated in various experimental conditions. The correlation between the adsorption characteristics of rare earths and transition metal on the resins and stability constants of complexes with macrocyclic ligand have been examined. The uranium ion was not adsorbed on the resins below pH 2.0, but the power of adsorption of uranium ion increased rapidly above pH 3.0. The adsorption power was in the order of 1%, 5% and 15%-crosslinked resin, but adsorptive characteristics of resins decreased in proportion to the order of dielectric constants of solvents.

• Nuclear Engineering and Technology
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• v.31 no.5
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• pp.445-454
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• 1999

This work describes the adaptation of extractive scintillation by URAE $X^{TM}$ with a photon-electron rejecting alpha liquid scintillation (PERAL $S^{)}$ spectrometer to the analysis of uranium in aqueous samples. The extraction efficiency of the system was evaluated under varing chemical conditions including pH, and sample-cocktail volume ratio. Isotopic information from the (PERAL $S^{)}$ spectrum of natural uranium was obtained using a curve fitting routine. Comparisons of the result with that obtained from alpha spectrometry method using ion implanted silicon detector showed good agreement.t.

• Environmental Engineering Research
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• v.7 no.3
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• pp.149-157
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• 2002