Field Study on Discharge of Natural Isotopes from the 238U and 232Th Series through Quaternary Deposit

This paper describes tentative results of the transport of natural radionuclides of the Uranium and Thorium series through Quaternary deposits in Sweden. Three drill holes between 10-16 meters deep were made down to bedrock and several radionuclides were measured in the dissolved, adsorbed and mineralogical phases. The isotope composition of the pore water differs from that of the soil minerals, which indicates that the origin of the isotopes is from discharging groundwater from bedrock. Less than 1 % of the isotopes exist in dissolved or adsorbed phases and the remaining fraction in minerals.