• Journal of Radiation Protection and Research
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• 제11권1호
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• pp.44-50
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• 1986

Tissue distribution and blood chemistry of uranium in serum levels of BUN, Creatinine, SGPT and SGOT were determined in rats after the administration of uranylnitrate. Determination of uranium in organ was done by radio activation analysis. Radioactivity of $^{239}Np$ in lung was higher than in other tissues (e.g. liver, kidneys, spleen, tibia, testes, stomach and brain). Correlations between BUN and Creatinine were positively increased after the administration of 25 mg/kg uranylnitrate. The SGPT and SGOT activities showed weak correlation with the control group. However, activities of SGPT and SGOT after the administration of lmg/kg uranylnitrate showed high peak at 90 min interval. Uranium uptake by liver and kidneys increased at early period and decreased immediately to the control level. Lung who confirmed to be the critical organ on toxic effect by uranylnitrate.

• The Journal of Engineering Geology
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• 제21권2호
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• pp.163-178
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• 2011

A test borehole was drilled in the Cheongwon area to investigate the relationship between geochemical environment and the natural occurrence of radioactive materials (uranium and Rn-222) in borehole groundwater. The borehole encountered mainly biotite schist and biotite granite, with minor porphyritic granite and basic dykes. Six groundwater samples were collected at different depths in the borehole using the double-packed system. The groundwater pH ranges from 5.66 to 8.34, and the chemical type of the groundwater is Ca-$HCO_3$. The contents of uranium and Rn-222 in the groundwater are 0.03-683 ppb and 1,290-7,600 pCi/L, respectively. The contents of uranium and thorium in the rocks within the borehole are 0.51-23.4 ppm and 0.89-62.6 ppm, respectively. Microscope observations of the rock core and analyses by electron probe microanalyzer (EPMA) show that most of the radioactive elements occur in the biotite schist, within accessory minerals such as monazite and limenite in biotite, and in feldspar and quartz. The high uranium content of groundwater at depths of -50 to -70 m is due to groundwater chemistry (weakly alkaline pH, an oxidizing environment, and high concentrations of bicarbonate). The origin of Rn-222 could be determined by analyzing noble gas isotopes (e.g., $^3He/^4He$ and $^4He/^{20}Ne$).

• The Journal of Engineering Geology
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• 제24권4호
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• pp.535-550
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• 2014

The origins and varieties of natural radioactive materials, including uranium and radon-222, were examined in a drilled borehole extending to a depth of 120 m below the surface in the Goesan area. In addition to core samples, eight groundwater samples were collected at different depths, using a double packer system and bailer, and their geochemical characteristics were determined. Most of the rock samples from the drilled core consisted of granite porphyry, with sedimentary rocks (slate, carbonate, or lime-silicates) and pegmatite occurring in certain sections. The pH of samples varied from 7.8 to 8.4, and the groundwater was of a Na-$HCO_3$type. Uranium and thorium concentrations in the core were < 0.2-14.8 ppm and 0.56-45.0 ppm, respectively. Observations by microscope and an electron probe microanalyzer (EPMA) showed that the mineral containing the natural radioactive materials was monazite contained in biotite crystals. The uranium, which substituted for major elements in the monazite, appeared to have dissolved and been released into the groundwater in a shear zone. Concentrations of Radon-222 in the borehole showed no close relationship with levels of uranium. The isotopes of noble gases, such as helium and neon, would be useful for analyzing the origins and characteristics of the natural radioactive materials.

• Nuclear Engineering and Technology
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• 제25권2호
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• pp.255-258
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• 1993

A method for analysis of trace uranium in urine sample was studied using a time-resolved $N_2$-laser-induced fluorimetry. The Fluran solution was found to be efficient to mask the chloride ions which are known to quench uranium fluorescence in the fluorimetric assay of uranium in urine. This improved method made the sample preparation much simpler than other conventional ones. The fluorescence intensities at 1% urine mixture with 10% Fluran aqueous solution showed good linearities in the concentration range of 10-500 ppb(before dilution).

• The Journal of Engineering Geology
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• 제23권4호
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• pp.477-491
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• 2013

Natural radionuclides in groundwater in the Danyang area were investigated to characterize the behaviors of uranium and radon with respect to lithology and physico-chemical components, which can aid our understanding of their occurrence, properties, and origins. To this end, a total of 100 groundwater samples were collected and analyzed, and radionuclide levels were used to construct detailed concentration maps. The water type of the groundwater, assessed using a Piper diagram, is mainly Ca-Na-$HCO_3$. The concentrations of uranium range from 0.02 to $251.0{\mu}g/L$ (average, $3.85{\mu}g/L$) and only 1% exceed USEPA's MCL (Maximum Contaminant Level). Uranium is enriched in groundwaters of Cretaceous granites and Precambrian metamorphic rocks, whereas it is depleted in groundwaters of sedimentary rocks. The concentrations of radon range from 13 to 28,470 pCi/L (average, 2397 pCi/L). Only 15% of the samples exceed AMCL (Alternative Maximum Contaminant Level) of 4000 pCi/L. The radon concentration is highest in groundwater of Cretaceous granites and lowest in groundwater of sedimentary rocks. In conclusion, the distribution and occurrence of radionuclides are intimately related to the basic geological characteristics of the rocks in which the radiogenic minerals are primarily contained. The behavior of uranium is only weakly related to that of radon (correlation coefficient = 0.15). There are also weak correlations between radionuclides and the main chemical components, pH, EC, Eh, and well depth. Of note, the correlation coefficient between radon and $SiO_2$ is 0.68, and that between radon and $HCO_3$ is -0.48. Factor analysis shows that radionuclides behave somewhat independently of each other because there are no significant factors that control the behavior of chemical components as well as radionuclides. The detailed concentration maps during this study will be used to establish useful database of radionuclide distribution and geological properties throughout Korea.

• The Journal of Engineering Geology
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• 제28권4호
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• pp.593-603
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• 2018

The most of groundwater with high U-concentration occur in the Jurassic granite of Gyeonggi massif and Ogcheon belt, and some of them occur in the Cretaceous granite of Ogcheon belt. On the contrary, they do not occur in the Jurassic granite of Yeongnam massif and the Cretaceou granite of Gyeongsang basin. The Jurassic and Cretacous granite, the host rock of high U-groundwater, were resulted from parental magma with high ratio of crustal material and highly differentiated product of fractional crystalization. These petrogenetic characteristics explain the geological evidence for preferential distribution of uraniferous groundwater in each host rock. It were reported recently that high U-content, low Th/U ratio and soluble mineral occurrence of uraninite in the two-mica granite of Daejeon area which have characteristics of S-type peraluminous and highly differntiated product. It is the mineralogical-geochemical evidences supporting the fact that the two-mica granite is the effective source of uranium in groundwater. The biotite granite and two-mica granite of Jurassic age were reported as biotite granite in many geological map even though two-mica granite occur locally. This fact suggest that the influence of two-mica granite can not be ignored in uraniferous groundwater hosted by biotite granite.

• Korean Journal of Materials Research
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• 제5권8호
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• pp.966-978
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• 1995

Amidoximated composite fiber adsorbents were prepared for separation of uranium from seawater and characterized by various instrumental techniques, such as IR spectroscopy, CHN elemetal analyzer and SEM. The swelling ratios and yields of the AN-TEGMA and AN-TEGMA-DVB copolymers were decreased with an increase in crosslinklng agents, such as DVB and TEGMA composition. The yield of 85-92% and 82-88% of AN-TEGMA and AN-TEGMA-DVB copolymers respectively were found. The porosity was also decreased with increase in crosslinking compositions, and it was found that the AN-TEGMA-DVB porosity copolymers were smaller than the value of AN-TEGMA copolymer. We investigated that the adsorbent with the composite fiber adsorbents were well dispersed on the surface of Its by SEM. The optimum contents of containing adsorbent in the copolymer was 40 weight percent. The capacity of uraniyl ion through the composite fiber adsorbent containing the amidoxime group was miximized a pH level of 8. Also, if was found that the synthesized composite fiber adsorbent was good material, due to a pH level of 8.3 of seawater, for separation of uraniyl ion from seawater.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• 제4권2호
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• pp.179-186
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• 2006

Chemical wastes are generated from nuclear facilities and R&D laboratories, but the uranium concentration in the final dried cake is evaluated into 11.2 Bq/g, which exceeds the exemption level of 10 Bq/g for each U isotopes, so the cake is categorized into a radioactive waste. Acid dissolution was applied to extract uranium from the waste sludge, and uranium adsorption on the dissolved solution was experimented by using IRN-77 and Diphosil bead. A large amount of resin was required to get above 80% of uranium removal, which was found to be due to a large amount of metal ions simultaneously dissolved from the precipitates with uranium. As an alternative method, acid dissolution is applied to the dewatered wet cake of the sludge, and the natural evaporation method is adopted for the dissolved solution. The uranium concentration of the dissolved solution was estimated to be 6.97E-01 Bq/ml, and the specific activity of the final waste sheets is evaluated to be 4.3 Bq/g. These results lead to the suggestion that the application of acid dissolution to the wet cake and the natural evaporation for the dissolved solution is an effective treatment method for chemical wastes containing uranium.

• Analytical Science and Technology
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• 제25권2호
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• pp.146-151
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• 2012

An analytical method was developed for the measurement of uranium isotope in ground water using the liquid scintillation counting technique. A LKB Wallac Quantulus 1220 liquid scintillation counter (LSC) equipped with pulse shape analyzer (PSA) and a solvent extraction method were used for the measurement of uranium isotope in ground water samples. The effect of solution volume on the extraction efficiency was evaluated for 100 to 1000 mL solutions using a NIST standard reference material (NIST SRM 4321C). The effect of groundwater pH on the extraction efficiency was also investigated for pH ranging from 0.5 to 10. It was found that the extraction efficiency had a strong dependence on pH showing a maximum at pH 2. In contrast, the effect of groundwater volume on the extraction efficiency was negligible in the range investigated. According to the method, the extraction efficiency of uranium isotopes was near 96% and the lower detection limit for uranium was 0.018 Bq/L with the counting time of 300 min. The result of this study was also verified by the conventional ICP-MS measurement. It is demonstrated that the suggested method is valuable to the determination of the optimum extraction and measurement conditions for uranium in ground water. The method was successfully applied to the ground water at four locations near the Daejeon province. It was found that the uranium content and the isotopic ratio of $^{234}U/^{238}U$ at the locations ranged 0.59~6.69 Bq/L and 0.72~1.40, respectively.

• Proceedings of the Mineralogical Society of Korea Conference
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• 한국광물학회.한국암석학회 2005년도 공동학술발표회 논문집
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• pp.138-143
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• 2005