Abstract

Mineralogical composition, ¹³⁷Cs activity, total organic carbon (TOC), and particle size of marine sediments near Wuljin Nuclear Powerplant were analyzed and the relationships among those components were investigated. The particle sizes of sediments were equivalent to sand size and in the range of -0.48~3.6 Mdφ. TOC contents and ¹³⁷Cs activities were in the range of 0.06~1.75% and minimum detectable activity (MDA) ~4.0 Bq/kg-dry with the average value of 1.15±0.62 Bq/kg-dry, respectively. The sediments in study area were characterized by large particle size and small TOC contents, and ¹³⁷Cs activity compared with other marine sediments. The main mineral components were quartz and feldspar (albite, microcline, and small amount of orthoclase) with small amount of pyroxene,
calcite, hornblende. Minerals with 10 ? XRD peak (mainly biotite) and chlorite were also identified. Among those minerals, biotite shows the linear relationship with ¹³⁷Cs content probably due to the frayed edge site (FES) on biotite or small amount of mixed illite. However, TOC content shows most linear relationship with ¹³⁷Cs content because no significant amount of clay minerals, which can adsorb significant amount of Cs, were observed in the study area, indicating that the distribution of ¹³⁷Cs in this study area was more significantly affected by the TOC content than mineral composition.

Keywords marine sediment, mineral composition, ¹³⁷Cs, TOC, particle size