The influence of long-term radiation irradiation on changes in composition, physical and chemical activity and mechanical properties of Lower Cambrian blue clays serving as the base of low-activity waste storage facilities has been analyzed. It is shown that as a result of formation of defects in the crystal lattice of rock-forming and cementing minerals and their amorphization there is a significant decrease in the values of the total deformation modulus and shear resistance parameters, absorption capacity and swelling ability of clays increases 2 times. It was noted that the thickness of these clays is characterized by a high content of bacterial mass, which indicates active microbiological activity, especially in the upper part of the section.
