Characteristics of Occurrence and Distribution of Natural Radioactive Materials, Uranium and Radon in Groundwater of the Danyang Area

Abstract

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 µg/L (average, 3.85 µg/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.

Determination of Uranium Concentration in Solid- and Liquid-state Geological Materials by Fission Track Registration Technique and its Applicability

“…(1) Taylor & McLennan (1995); (2) Koljonen (1992); (3) Tauber (1988); (4) Thalmann et al (1988); (5) Reimann et al (1996); (6) Cho et al (2013); (7) Lide (1996). *Uranium concentration=Median value.…”

Performance Evaluation of Natural Radioactivity of Mine Wastes Using Various Shielding System

“…또한 흑색셰일이 분포하는 주변 지하수내에 우라늄, 라 돈 등의 자연방사성물질 분포특성에 관한 연구가 수행되 었으며 (Shin et al, 2002;Hwang J, 2010;Cho et al, 2013), 암석, 토양 및 식물의 특성규명뿐만 아니라 이러 한 지역을 복원하기 위하여 여러 가지 방법들을 적용하 여 그 효율성을 제시하는 연구도 진행되고 있다 (Chang and Lee, 2008).…”