Marek Duliński, Zbigniew Gorczyca, Michał Marzec, Robert Czub and Krzysztof Brudnik
A comparison of two methods of radiocarbon age determination of groundwater is presented. The simplest Pearson model and the “user-defined” option of the NETPATH program were considered. Both methods were used to determine the age of water from a PZ-2 piezometer that is situated in the foreground of chamber Z-32 in Wieliczka Salt Mine. Results of these calculations clearly demonstrate that 14C ages obtained by the Pearson model can be significantly overestimated in comparison with those determined by the NETPATH code. Without additional data, such as the stable isotope composition of the water, conclusions on the age of the groundwater based solely on the Pearson model may be highly inadequate.
The isotope activity concentration of rocks and bottom sediments was evaluated based on the samples collected from sedimentation ponds and gangue repositories. Radium 226Ra, thorium 228Th and potassium 40K activities were measured by gamma spectrometry using high-purity germanium detector – HPGe 4020. The radiation effect resulting from the presence of natural radionuclides was estimated by radiological hazard indices such as f1 and f2 coefficients, radium equivalent, internal and external hazard indices and absorbed dose rate. Performed measurements and calculations have shown that the bottom sediments are most contaminated. They may pose a serious radiological hazard for present and future generations.