Activation of Biological Shields

Abstract

Knowledge of the quantities of radioactive waste resulting from the dismantling of the concrete biological shields of nuclear reactors is very approximate because there is little accurate data available on the composition of the concrete. It is possible to calculate the residual radioactivity in the concrete from nuclear reactors if the amounts of elements which give rise to long-lived radionuclides, and in particular chlorine, calcium, nickel, cobalt, niobium, europium and samarium are known accurately. The highly effective techniques of neutron activation analysis were used to determine the quantities of 29 elements in 21 concrete samples from reactors in the European Community. Research was conducted on the Lingen (KWL) and Gundremmingen (KRB-A) reactors. The method employed consisted of measurements conducted on concrete samples and calculations based on the composition of the concrete determined by activation analysis. The measurements made and the results of the calculations are in reasonable agreement.