The activity concentrations of 238U, 234U, 230Th, 226Ra, 232Th, and 228Th in thermal spring waters in the Tatun volcanic area were determined. Parameters including acidity, Cl- and {SO42- concentrations in spring waters at the sampling sites have been investigated to allow interpretation of the migration of the radionuclides, and to elucidate the influence of these parameters on the variations of radionuclide contents. Radioactive disequilibria were found in uranium and thorium series in thermal spring waters. The contents of uranium and thorium decreased with increasing pH. The ratios of 230Th/ 234U, 226Ra/ 230Th and 228Th/ 232Th show significant disequilibria. The 226Ra/ 230Th ratio (0.6034.8) decreased with the Cl- or {SO42- concentration. All 228Th/ 232Th ratios (1.019.49) deviated from unity due to the co-precipitation of 228Ra with barium and lead sulfate.
Print ISSN: 0033-8230
Volume: 91, 07/2003
Pages: 403