The minerals belonging to the montmorillonite group were studied. Under irradiation werp air-dry minerals as well as those in solutions containing 90Sr, which gave us an opportunity to study the irradiation influence on the soprtion accumulation of radionuclides. The analysis of the diffractograms of irradiated and nonirradiated minerals shows that the structure of the minerals belonging to the montmorillonite group remains unchanged, while alumosilicate layers converge which results in a decrease in interplane distance.