Аннотация:Some results of induced dose rate and activity at several cooling time up to 1000 years for Pb-nat, Pb-208, Bi-209 and Na-23 are presented. According to these results, it might be concluded that radiotoxicity of Pb-208 coolant decays essentially faster than one of Pb-nat or Na-23, that is very important for the problem of reactor decommissioning and accidents connected with coolant losses.