DETERMINATION OF THE ACTIVITY OF LONG-LIVED 41Ca IN REACTOR BIOLOGICAL SHIELDING MATERIALS BY PHOTOACTIVATION METHOD

Abstract

The paper discusses a photoactivation method for determining the activity of the long-lived isotope 41Ca relative to the activity of 60Co in irradiated reactor biological shielding concrete. It is proposed to use photonuclear reactions on cobalt and calcium isotopes: 59Co(γ, 𝑛)58Co, 44Ca(γ, 𝑝)43K or 48Ca( γ, n)47Ca→47Sc. to determine the activity of 41Ca. The sensitivity of the proposed method is of the order of ∼10-6 Bq/g, provided that semiconductor spectrometers with an ultrapure germanium detector are used. The structure and chemical composition of the sample do not affect the proposed method. It avoids the long sample preparation times associated with radiochemical methods.