• Fire Science and Engineering
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• v.26 no.6
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• pp.15-23
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• 2012

Indirect Test Method is often used instead of direct test method in test method for extinguishing performance of $CO_2$ extinguishing facility because of high cost, environment problems and difficulties of procedure. But in the danger facilities for a unit of nation, such as a petrochemical plant, a nuclear power plant, or etc. is better to verify the performance of the extinguishment through direct discharge test. In $CO_2$ extinguishing system for total flooding system installed in dangerous facilities in Korea, each protected area in surface fire and deep-seated fire had selected and verified of extinguishing performance of $CO_2$ extinguishing facilities. To get recognized as extinguishing performance, discharged $CO_2$ concentration to protected area should be equivalence with design concentration standards (NFSC and NFPA). The Design Concentration means that $CO_2$ extinguishing agent is considerate of concentration for percentage of allowance (20 %) from extinguishing concentration which available to control of flame. As test result, surface fire and deep seated fire in protected area is obtained $CO_2$ design concentration and maintained design concentration more than 20 minutes as deep-seated fire. Through this study, we introduced direct discharging test method and decision method. And furthermore, especially in the dangerous facilities as a unit of Nation, we suggested necessity about reliability of extinguishing facilities to use direct test method.

• 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.34 no.1
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• pp.71-88
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• 2001

The Geochemica] and isotope studies on the $CO_2$-rich water from the Shinchon area were carried out. The Shinchon $CO_2$-rich water belongs to Ca(Na)-$HCO_3$ type showing very high $P_{CO_{2}}$ ( $10^{-0.35}$ ~ $10^{0.29}$ atm) and TDS (835-3,144 mg/L). The results of geochemical and isotope analysis indicate that $CO_2$ gas is originated from the deep seated source such as mantle or magmatic gases. The $CO_2$-rich water was evolved by interaction with deep-seated granite and major water-rock interaction was dissolution of p]agioclase resulting high Na content of $CO_2$-rich water. Precipitation and dissolution of secondary calcite might be accompanied with the dissolution of plagioclase maintaining Na/Ca ratio. High contents of K and $SO_4$ indicate that the geochemical characteristics of $CO_2$-rich water were partially affected by interaction with upper sedimentary rock during uprising to surface. N03 and tritium contents suggest that the $CO_2$-rich water was mixed with low $CO_2$ groundwater at some locations. The oxygen-hydrogen isotopes show that all water samples were derived from meteoric waters and the $CO_2$-rich water was isotopically re-equilibrated with lighter $CO_2$ gas. Although some carbon isotope data show isotopically heavy values, carbon isotope data indicate that the $CO_2$ gas was possib]y derived by deep source.

• Economic and Environmental Geology
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• v.24 no.4
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• pp.335-346
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• 1991

It is observed that calcareous nodules of the Hwajeol Formation are locally skarnized in the Sangdong district, in which the skarn mineralization extends 5 Km westward from the Sangdong mine area to the Hwajeolchi area. After a hidden granite beneath the Sangdong mine was discovered by exploration drillings, the exploration teams of the Sangdong mine and the Korean Mining Promotion Corporation have assumed that the skarn nodule of the Hwajeol Formation was derived from emplacement of a granite in deep place and the occurrence of hidden ore bodies below the skarn, and they have discovered high grades of tungsten orebody in the same horizon of the Sangdong ore body. Mutual genetic relatioships between epidote and garnet may be explained by following chemical reactions $Ca_2FeA_{12}$ $Si_3O_{12}(OH)+CaCO_3=Ca_3(Fe,\;Al)_2$ $SiO_{12}+1/2CO_2+1/2H^+Ca_3FeSi_3O_{12}+SiO_2+CO_2=2CaFeSi_{12}O_6+CaCO_3+1/2O_3$. It is concluded that epidote and garnet are useful as target minerals indicating a potential occurrence of deep seated hidden ore body. Since the epidote may inform the emplacement of the granite, while the garnet in the skarn nodule of the Hwajeol Formation may reflect a strong hydrothermal mineralization taking place from the depth.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.87-90
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• 2000

The hydrogeochemical and isotopic studies on deep groundwater in the Munkyeong area, Kyeongbuk province were carried out. $CO_2$-rich groundwater (Ca-HC $O_3$ type) is characterized by low pH (5.8~6.5) and high TDS (up to 2,682 mg/L), while alkali groundwater (Na-HC $O_3$ type) shows a high pH (9.I~10.4) and relatively low TBS (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 HC $O_3$ concentrations are enriched. The low Pc $o_2$ (10$^{-6.4}$atm) of alkali groundwaters seems to result from the dissolution of silicate minerals without a supply of $CO_2$. The $\delta$$^{18}$ O and $\delta$D values and tritium data indicate that two types of deep groundwater were both derived from pre-thermonuclear meteoric water. The carbon Isotope data show that dissolved carbon in the $CO_2$-rich water was possibly derived from deep-seated $CO_2$ gas. The $\delta$$^{18}$ 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 130~175$^{\circ}C$. 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.m.

• The Journal of Engineering Geology
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• v.22 no.1
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• pp.123-134
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• 2012

Hydrochemical analyses, carbon isotopic (${\delta}^{13}C_{DIC}$) analyses, and noble gas isotopic ($^3He/^4He$ and $^4He/^{20}Ne$) analyses of the Dalki carbonate waters in the Chungsong area were carried out to elucidate their hydrochemical composition and to determine the source of $CO_2$ gas and noble gases. The carbonate waters have a pH of between 5.93 and 6.33, and an electrical conductivity 1950 to $3030{\mu}S/cm$. The chemical composition of all carbonate waters was Ca(Mg)-$HCO_3$, with a high Na content. The contents of Fe, Mn, and As in some carbonate waters exceed the limit stipulated for drinking water. The concentrations of major ions are slightly higher than those reported previously. The ${\delta}^{13}C_{DIC}$ values range from -6.70‰ to -4.47‰, indicating that the carbon originated from a deep-seated source. The $^3He/^4He$ and $^4He/^{20}Ne$ ratios vary from $7.67{\times}10^{-6}$ to $8.38{\times}10^{-6}$ and from 21.32 to 725.7, respectively. On the $^3He/^4He$ versus $^4He/^{20}Ne$ diagram, the noble gas isotope ratios plot in the field of a deep-seated source, such as mantle or magma. We therefore conclude that $CO_2$ gas and noble gas in the Dalki carbonate waters originated from a deep-seated source, rather than an inorganic $CO_2$ origin as suggested in a previous study.

• Economic and Environmental Geology
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• v.35 no.2
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• pp.121-136
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• 2002

The $CO_2$-rich springs in the Kyungpook Province has been found at 16 locations. Most of the $CO_2$-rich springs outflow along either fault zones or the geologic boundary between Mesozoic granites and their adjacent rocks. The $CO_2$-rich water samples show a high $CO_2$ concentration ( $P_{CO2}0.46 to 5.21 atm), weak acidic pHs, wide electrical conductivity values ranging from 422 to 2,280 $\mu\textrm{S}$/cm, and high re content. They are classified into the ca-HC $O_3$ type in chemical composition.$\delta$$^{18}$ O and $\delta$$^2$H data indicate that $CO_2$-rich water is meteoric origin. The $\delta$$^{13}$ C values (-1.5$\textperthousand$ to -6.1$\textperthousand$ PDB) suggest that dissolved $H_2$C $O_3$$^{0}$ C $O_3$- are mainly derived from a deep-seated $CO_2$ and carbonate minerals. The thermodynamic equilibrium state between $CO_2$-rich water and major minerals, and hydrochemical characteristics indicate that major source minerals determining the chemical composition of $CO_2$-rich water are carbonate minerals, plagioclase, K-feldspar and Fe-oxides. Under high $CO_2$ pressure and the weak acidic condition, most of the $CO_2$-rich water samples are thermodynamically in the dissolution state with respect to albite and carbonate minerals.

• The Journal of Engineering Geology
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• v.21 no.1
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• pp.65-77
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• 2011

Hydrochemical and carbon isotopic (${\delta}^{13}C_{DIC}$) analyses of 11 water samples, and noble gas isotopic analyses of 8 water samples collected in the Kyeoungbuk and Kangwon areas of Korea were performed to determine their hydrochemical characteristics and to interpret the source of noble gases and $CO_2$ gas in the water. The carbonated mineral waters are weakly acidic (PH = 5.59-6.04), and electrical conductivity ranges from 302 to $864\;{\mu}S/cm$. The chemical composition of all the water samples is Ca-$HCO_3$ type. The high contents of Fe and Mn exceed the safe limits for drinking water. The ${\delta}^{13}C_{DIC}$ values of the samples range from -5.30‰ to -2.84‰, indicating that the carbon is supplied mainly from a deep-seated source and to a lesser degree from an inorganic carbonate source. The $^3He/^4He$ ratios of the samples range from $1.51{\times}10^{-6}$ to $6.45{\times}10^{-6}$. The samples plot into three groups on a $^3He/^4He$ versus $^4He/^{20}Ne$ diagram: the deep-seated field (e.g., a mantle source), the atmospheric field, and the air-mantle mixing field. A wide range of $^4He/^{20}Ne$ ratios is observed ($0.036{\times}10^{-6}$ to $1.76{\times}10^{-6}$), indicating that while radiogenic $^4He$ is dominant in these water samples, mantle-origin He is also present. The supply of $CO_2$ gas and noble gases from a deep-seated source to carbonated waters is inferred to be controlled by geological structures such as faults and geological boundaries.

• Economic and Environmental Geology
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• v.32 no.5
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• pp.455-468
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• 1999

Carbonated mineral waters fo $Ca(Mg)-HCO_3$ type spring out fissure of Jurassic granite in the valley floor of the Chungsong area. The water has been long as a Dalki medicinal water because of its unique therapeutic effect against clacium deficit, stomach and skin troubles, ect. The water has a high $CO_2$ concentration ($P_{CO_2}$=0.51~1.12atm) and exhibits strong pH buffering (5.9~6.26) by $H_2CO_3/HCO_3$ couple. Electrical conductivity ranges from 1,900 to 3100 $\mu$S/cm. Environmental isotopic data $(^{2}H/^{1}H, ^{18}O/^{16}O \;and \;^3H)$ indicates that the water is of meteoric origin recharged in the Cretaceous sedimetary strata distributed in upper part of the catchment area at least before 1950s, The high $P_{co_2}$ and carbon isotope data (${\delta}^{13}C=-3\sim-0.2\textperthousand$) suggest that the potential source of carbonated mineral water was originated in deep-seated $CO_2$ as wel as aboundant carbonate minerals of sedimentary desimetary rocks. The major source minerals of the dissoved species in the carbonated mineral water appear to be carbonate minerals, albite and K-feld-spar in sedimentrary rocks.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.159-170
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• 1999

The hydrogeochemical study on the $CO_2$-rich water in the Chojeong area was carried out. The $CO_2$-rich water of Ca-$HCO_3$type is characterized by low pH (5.0~5.8). high $CO_2$concentration ($Pco_2$＜$10^{0.31}$atm) and high TDS. The water chemistry indicates that the $CO_2$-rich water was probably evolved by the local suppy of deep seated $CO_2$gas resulting in the enhanced water/rock (granite) interaction under low pH conditions. High $NO_3$concentration indicates that the $CO_2$water was mixed and diluted with low $CO_2$groundwater in the vicinity of the area, in which the extensive groundwater abstraction occurred during the past years. The evoiution of the $CO_2$-rich water in the Chojeong area for the process of $CO_2$injection water/rock interaction and mixing processes was thermodynamically simulated by PHREEQC. Although the simulation was limited to water/plagioclase interaction, the results show the feasible explanation about the observed trend of pH and Ca and Na concentrations of the $CO_2$-rich water.