US EPA

1427186 

Technical Report 

Retardation of uranium-238 and thorium-232 decay chain radionuclides in Long Island and Connecticut aquifers 

Copenhaver, SA; Krishnaswami, S; Turekian, KK; Epler, N; Cochran, JK 

1993 

International Programme on Chemical Safety (IPCS) 

BIOSIS/93/13812 

57 

3 

597-603 

eng 

BIOSIS COPYRIGHT: BIOL ABS. Knowledge of the ability of an aquifer to retard the groundwater transport of toxic or radioactive ions can be inferred from the analysis of groundwater for the radionuclides of the 238U- and 232Th-decay chains. Groundwaters of varying chemical composition were analyzed from wells in Long Island, New York, and Connecticut (USA). Aquifer lithologies are arkose, quartz sandstone, granite, and glacial drift. Adsorption (k1) and desorption (k2) coefficients for Ra and Pb were calculated using 222Rn activity as a measure of the supply of other alpha-recoil nuclides. Laboratory tests of the validity of this assumption were made by measuring the flux of 224Ra and 222Rn from aquifer solids. The ratio k1/k2 is the distribution coefficient, K, which is effectively equal to Rf, the retardation factor. The average value of K for Ra is 6Island aquifers and 5efficient for Pb is 104 in Long Island and 105 in Connecticut. Results from this and other studies reveal a strong dependence 

Radiation-Radiation and Isotope Techniques; Ecology; Movement (1971- ); Toxicology-Environmental and Industrial Toxicology; Public Health: Environmental Health-Radiation Health