• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.22 no.1
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• pp.45-54
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• 2024

Currently, off-site dose calculations for nuclear power plants are conducted using a computer program (K-DOSE 60). The program is developed based on the regulatory guidelines of the Korea Institute of Nuclear Safety (KINS), which is a domestic nuclear regulatory agency. In this study, a domestic application of the International Atomic Energy Agency (IAEA) TRS (Technical Reports Series)-472 methodology for ³H and ¹⁴C in liquid effluents was studied. The dose-evaluation methods adopted and the program configuration for dose evaluation are described based on ³H and ¹⁴C in the liquid-effluent-evaluation module of the computer program. The accuracy of the program is verified by comparing the program-calculated results with hand calculation values. Furthermore, a comparative evaluation with LADTAP II, which is a liquid-effluent-evaluation methodology developed by the U.S. NRC (Nuclear Regulatory Commission), is performed. The result confirms that the program-calculated results for the IAEA TRS-472 methodology are consistent with the hand calculation values. Meanwhile, the result of comparative evaluation with LADTAP II indicates different results depending on the methodology used.

• Natural Product Sciences
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• v.11 no.1
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• pp.45-49
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• 2005

Previously, a flavonoid fraction, which consisted mainly of protocatechuic acid, fustin, fisetin, sulfuretin, and butein, here named RCMF [${\underline{R}}hus$ verniciflua Stokes (RVS) ${\underline{c}}hloroform-{\underline{m}}ethanol\;{\underline{f}}raction$], was prepared from a crude acetone extract of RVS which is traditionally used as a food additive and as an herbal medicine. In the present study, we investigated the effects of $TNF-{\alpha}$ on RCMF-induced growth inhibition and apoptosis induction using human osteosarcoma (HOS) cells. The results from tritium uptake and MTT assays showed that $TNF-{\alpha}$ treatment itself (10 ng/ml) did not induce any cytotoxicity, but it actively accelerated RCMF-mediated cytotoxicity of HOS cells. RCMF-induced cytotoxicity and its facilitation by $TNF-{\alpha}$ was verified to be apoptotic, based on the increased DNA fragmentation and low fluorescence intensity in nuclei after propidium iodide (PI) staining of HOS cells. This speculation was further demonstrated by monitoring the Annexin V/PI double staining which could discriminate the difference between apoptotic and necrotic deaths. Collectively, our findings indicate that $TNF-{\alpha}$ accelerates RCMF-induced cytotoxicity in HOS cells.

• Economic and Environmental Geology
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• v.33 no.6
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• pp.469-489
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• 2000

The hydrogeochemical and isotopic studies on deep groundwater (below a 550 m depth from the ground surface) in the Munkyeong area, Kyeongbuk province were carried out. Two types of deep groundwater (${CO_2}$-rich groundwater and alkali groundwater) occur together in the Munkywong area. ${CO_2}$-rich groundwater (Ca-${HCO_3}$ type) is characterized by low pH (5.8~6.5) and high TDS (up to 2,682 mg/L.), while alkali groundwater (Na-${HCO_3}$ type) shows a high pH (9.1~10.4) and relatively low TDS (72~116 mg/L). ${CO_2}$-rich water may have evolved by ${CO_2}$ added at depth during groundwater circulation. This process leads to the dissolution of surrounding rocks and Ca, Na, Mg, K and ${HCO_3}$ concentrations are eniched. The low $Pco_2$ ($10^{-6.4}$atm) of alkali groundwaters seems to result from the dissolution of silicate minerals without a supply of ${CO_2}$. The ${\delta}^{18}O$ and ${\delta}^D$values and tritium data indicate that two types of deep groundwater were both derived from pre-thermonuclear meteoric water and have evolved through prolonged water-rock interaction. The carbon isotope data show that dissolved carbon in the ${CO_2}$-rich water was possibly derived from deep-seated ${CO_2}$ gas, although further studies are needed. The ${\delta}^{34}S$ values of dissolved sulfate show that sulfate reduction occurred at great depths. The application of various chemical geothermometers on ${CO_2}$-rich groundwater shows that the calculated deep reservoir temperature is about 130~$l75^{\circ}C$. Based on the geological setting, water chemistry and environmental isotope data, each of the two types of deep groundwater represent distinct hydrologic and hydrogeochemical evolution at depth and their movement is controlled by the local fracture system.

• Economic and Environmental Geology
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• v.33 no.6
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• pp.491-504
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• 2000

Environmental isotope $^{18}O$, $^{2}H$, $^{3}H$,$^{13}C$, $^{34}S$and $^{87}Sr/^{86}Sr$) studies on ${CO_2}$-rich waters in the Kangwon Province were carried out to elucidate the origin, residence time, water-rock interaction and mixing process of their. ${\delta}^{18}O$ and ${\delta}D$ data indicate that ${CO_2}$-rich waters were derived from the local meteoric water. It also shows that each type of ${CO_2}$-rich water has distinct isotopic composition and Na-${HCO_3}$ type water (-10.8 to -12.1${\textperthousand}$, ${\delta}^{18}O$ ) is lighter than other type waters. These depleted isotopic values supposedly indicate that, considering the altitude effect of isotope in Korea, the recharge area of Na-${HCO_3}$ type water can be estimated to be relatively higher in elevation than those of Ca-${HCO_3}$ and Ca-Na-${HCO_3}$ type waters. Tritium contents close to zero are observed in the Na-${HCO_3}$ type water, confirming a long residence time and the possibility of a ${CO_2}$ inflow into the aquifer at great depth. These isotope data also show that the Ca-${HCO_3}$ type water has undergone mixing process with surface water during ascending at depth, whereas Na-${HCO_3}$ type water was less mixed with surface waters. The carbon isotope data (-8.8 to ＋0.8 ${\textperthousand}$ ${\delta}^{13}C$) indicate that dissolved carbon in the ${CO_2}$-rich waters was possibly derived from deep seated ${CO_2}$ gas. The high ${\delta}^{34}S$ values (up to 38.1${\textperthousand}$) of dissolved sulfates suggest that sulfate reduction by microbial activity had occurred at depth. Strontium isotopic data ($^{87}Sr/^{86}Sr$) of ${CO_2}$-rich waters indicate that the chemistry of the ${CO_2}$-rich waters is determined by water-rock (granite) interaction.

• Economic and Environmental Geology
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• v.31 no.6
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• pp.485-498
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• 1998

The water-rock interaction and anthropogenic contamination affecting to geochemical composition of shallow and deep groundwaters were investigated in the agricultural area of Myunggok-ri, Kongju. The shallow groundwater is classified into the chemical types of $Ca-HCO_3$ and $Ca-Cl(SO_4)$ and shows weak acid having an average pH 6.2. Deep groundwater shows the uncontaminated composition of the chemical types of $Na-HCO_3$ and Na $(Ca)-HCO_3$ with pH of 8.4~8.8. The grouping approach of chemical data of waters shows the distinguished trend between water composition influenced anthrophogenic input and water composition mainly determined by natural process such as water-rock interaction. The main anthropogenic inputs affecting chemical composition of shallow groundwater are the contaminants such as $K^+$, $NO_3{^-}$, $Cl^-$ having average values of 4.4 mg/l, 22 mg/l, 13.7 mg/l, respectively. The contaminants were probably derived from fertilizer, sweage, septic tank, and stable, etc. The hydrogen and oxygen isotopic compositions indicate that five deep groundwaters were recharged from different altitudes, and that shallow and deep groundwaters were originated from meteoric water. Tritium contents of waters suggest that deep groundwater was recharged before or just after 1950s, and that shallow groundwater is much younger than deep groundwater. The results of this study may serve as a basic data for the future study of shallow groundwater as a drinking water in agricultural area, in Korea.

• Journal of Soil and Groundwater Environment
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• v.6 no.2
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• pp.15-22
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• 2001

Radiocarbon ($^{14}C$) and tritium in water have been applied to hydrogeology as a tool for dating of groundwater. The long half-life of $^{14}C$(5,730 years) makes it useful for evaluation of residence time of groundwater, However, the $^{14}C$ has not been applied to groundwater studies in Korea, owing to the absence of preparation line for $^{14}C$ analysis. By this time $^{14}C$ of groundwater has been analyzed mainly using benzene synthesizer, which is so complicate and time-consuming that has been is limitedly applied to hydrogeology. Recently, the direct $CO_2$ absorption method for $^{14}C$ analysis was developed and introduced to KAERI for the evaluation of domestic groundwater system. The results of $^{14}C$ in groundwater would be usefully applied to hydrogeological studies such as the well understanding of groundwater flow system in depth. The reliability of our $^{14}C$ data was confirmed by inter-comparison with the qualified international isotope laboratory.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.77-83
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• 2006

A gene encoding a $\gamma-butyrolactone$ autoregulator receptor was cloned from Saccharopolyspora erythraea, and the biochemical characteristics, including the autoregulator specificity, were determined with the purified recombinant protein. Using primers designed for the conserved amino acid sequence of Streptomyces $\gamma-butyrolactone$ autoregulator receptors, a 120 bp S. erythraea DNA fragment was obtained by PCR. Southern and colony hybridization with the 120 bp fragment as a probe allowed to select a genomic clone of S. erythraea, pESG, harboring a 3.2 kb SacI fragment. Nucleotide sequencing analysis revealed a 615 bp open reading frame (ORF), showing moderate homology (identity, $31-34\%$; similarity, $45-47\%$) with the $\gamma-butyrolactone$ autoregulator receptors from Streptomyces sp., and this ORF was named seaR (Saccharopolyspora erythraea autoregulator receptor). The seaR/pET-3d plasmid was constructed to overexpress the recombinant SeaR protein (rSeaR) in Escherichia coli, and the rSeaR protein was purified to homogeneity by DEAE-Sephacel column chromatography, followed by DEAE-ion-exchange HPLC. The molecular mass of the purified rSeaR protein was 52 kDa by HPLC gel-filtration chromatography and 27 kDa by SDS-polyacrylamide gel electrophoresis, indicating that the rSeaR protein is present as a dimer. A binding assay with tritium-labeled autoregulators revealed that rSeaR has clear binding activity with a VB-C-type autoregulator as the most effective ligand, demonstrating for the first time that the erythromycin producer S. erythraea possesses a gene for the $\gamma-butyrolactone$autoregulator receptor.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.317-320
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• 2005

More strict radioactive regulations are applied to Korean nuclear power plants (NPPs) since ICRP-60 recommendation for radiation protection and has been enforced since 2003. In particular. carbon-14 and tritium concentrations are significantly higher at CANDU reactors compared to PWR reactors and this increases the risk of internal radiation exposure to workers at CANDU NPPs. Thus, it is necessary to estimate the exact amount of internal radiation exposure to workers fur radiological protection at CANDU reactors. In this paper, the current dosimetry method for carbon-14 is analyzed for the establishment of internal dosimetry for carbon-14 at domestic NPPs.

• Journal of Soil and Groundwater Environment
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• v.23 no.4
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• pp.1-15
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• 2018

Despite of safety issues related to radiological hazards, 31 countries around the world are operating more than 450 nuclear power plants (NPPs). To operate NPPs safely, safety regulations from radiation protection organizations were developed and adopted in many countries. However, many cases of radionuclide releases at foreign NPPs have been reported. Almost all commercial NPPs routinely release radioactive materials to the surrounding environments as liquid and gas phases under control. These releases are called 'planned releases' which are planned, regularly monitored, and well documented. Meanwhile, the releases focused in this review, called 'unplanned releases', are neither planned nor monitored by regulatory and/or protection organizations. NPPs are generally composed of various structures, systems and components (SSCs) for safety. Among them, the SSCs near reactors are closely related to safety of NPPs, and typically fabricated to comply with stringent requirements. However, some non-safety related SSCs such as underground pipes may be constructed only according to commercial standards, causing the leakage of radioactive fluids usually containing tritium ($^3H$). This paper discusses SSCs of NPPs and introduces several cases of unplanned releases at foreign NPPs. The current regulation on the environmental radiological surveillance and assessment around the NPPs in South Korea are also examined.

• Journal of Environmental Science International
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• v.10 no.1
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• pp.47-58
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• 2001

According to the results of the groundwater quality investigation about 230 holes all over the country, the groundwater which was in excess of standard grows larger every year and closed holes increased to 23,457 holes in 1997 from 15,724 holes in 1996. This is the major reasons that water quality contamination, shortage of water quantity, increasing of salinity and so on. There are 7 groundwater salinization sources which are condisered as most important on a regional level. And among theses the Cheju Island groundwater salinization sources are (1) halite solution, (2) natural saline groundwater, (3) sea-water intrusion. The method of taking an isotopes is one of research methods of the origin of groundwater salinization and is used in so many studies because it has very high confidence. $^{18O}O, ^2H, ^3H, ^{14}C$ and so on in an isotopes are frequently used in the method of them. Consequently on this study we analyzed major ions and $^3H$ in groundwater, sea-water and rain of the eastern part of cheju island known as contaminated site from long time ago to examine the origin of groundwater salinization. Relation ratios of the major ions versus chloride ion shows similar tendency to sea-water. This indicates that sea-water entered the groundwater layer. And amount of $^3H$ in holes of the land side is higher than of the sea side. Relation of chloride ion versus $^3$H indicates negative character. Therefore we can think that the reason of groundwater salinization of this part is natural saline groundwater and halite solution by relation.