Time-dependent 241Am activity in the environment from decay of 241Pu released in the Chernobyl accident

The time-dependent activity of the alpha-emitting radionuclide 241Am, resulting from beta-decay of 241Pu present in the accidental release from Unit 4 of the Chernobyl NPP, has been studied. The ratios of the activity of 241Pu to those of 239, 240Pu and of 238, 239, 240Pu at the time of the accident have been derived as 69.6+0.6 and 47.1+0.4, respectively. Based on these results, a prediction of the future activity ratio 241Am/238,239,240Pu has been made, showing that it will increase slowly to the value 1 in the year 2005 and to a maximum value of 1.7 at the end of this century, followed by a gradual decrease.