Modelling the long-term dynamics of radionuclides in rivers
A model describing the long-term dynamics of radioactive contamination of rivers was developed. The radionuclide activity concentration in river water is assumed to be directly proportional to the content of the radionuclide exchangeable form in the surface layer of soil on the river catchment. The model input parameter values can be determined independently or estimated using results of the short-term observations. The modelled and measured 137 Cs activity concentrations in rivers contaminated as a result of the Chernobyl accident are in good agreement.
A healthy tissue tolerance study1,2 with Beagle dogs was carried out at the Finnish BNCT facility FiR 1 during February-March 1998. Three dose groups of dogs without boron carrier, each comprising five Beagles, and one dose group with BPA-F infusion were irradiated. Individual dose plans1 were done for each dog. The absorbed doses, which were actually delivered to healthy tissues, were monitored in vivo by placing the dosimeters on the shaved skin of the dogs or in the accessible cavities. In this study, absorbed gamma doses were monitored with thermoluminescent (TL) dosimeters, and neutron fluences were determined with activation foils. The obtained results were compared to the calculated values.