Measurement limits to 134Cs concentration in soil

We investigate the caesium concentrations in soils in mountain areas near Gori nuclear power plant in Korea, focusing on the measurement limits to the (134)Cs. In order to lower the minimum detectable amount (MDA) of activity for the (134)Cs, we have used the ammonium molybdophosphate (AMP) precipitation method to get rid of the (40)K existing in natural radioactivity, which reduces the MDA activity about 10 times smaller than those without the AMP precipitation method. The MDA results for the (134)Cs were found to be in the range between 0.015 and 0.044 Bq/kg-dry weight. In order to diminish the background, we also have measured a part of the soil samples in Yangyang, a small town in the east coast of Korea. However, it turns out that in order to detect the (134)Cs in the samples the MDA should be reduced to the level of mBq/kg-dry weight.