NAA FOR OPTIMIZATION OF RADIATION SHIELDING OF NUCLEAR-POWER-PLANTS

The results of activation studies of concrete ingredients for shieldin g structures of nuclear installations in the aspect of their decomm is sioning are given. It is shown that for the long-lived induced radioac tivity of construction mineral materials irradiated for 30 years and c ooled for more than one year such radionuclides as calcium, iron, coba lt, caesium and europium are responsible. Elemental content of the bin ding agent and raw material components for their production is obtaine d by neutron activation analysis. The results show that the type of th e binding agent influences to a great extent the concrete shielding ac tivity. The concentration of the above mentioned elements should be ta ken into account even at the stage of nuclear power plants design. It would allow one to make a prognosis on the volume and radioactivity of wastes as on the radioactivity effect felt by the staff engaged in th e decommissioning.