NEUTRON TOMOGRAPHY STUDIES OF CEMENT-BASED MATERIALS USED FOR RADIOACTIVE WASTE CONDITIONING

The internal structure of several promising cement-based materials for the conditioning of low and intermediate level radioactive waste (LILW) were studied using neutron tomography in order to assess the effectiveness and stability of the hardened cement matrix, taking in consideration the need for long term durability in disposal conditions. The spatial distributions of water-containing pores, as well as the arrangement of pores and cracks inside the studied cement-based matrices, were determined on the base of specific interactions of neutrons with various components of the cement samples and the application of modern mathematical algorithms for three-dimensional imaging data analysis. The distributions of the water-containing pores, the lengths and thicknesses of the selected cement-based samples were put in evidence, being a case study for optimizing the concrete matrix to be validated and further applied in the radwaste conditioning.