LAUSR

To have a clear cognition on whether clay could be used for disposal of high level radioactive waste efficiently or not, in this work, talc was irradiated by Co-60 γ ray in air at a dose rate of 54 Gy/min with doses up to 1000 kGy. Then, variations in chemical/crystalline structure and intrinsic mechanism were explored. Main results show talc occurred dehydroxylation and lattice shrink. Under 0–1000 kGy irradiation, shrink range in (002) lattice plane was near 1.5% close to 0.14 Å. Main mechanisms involve framework/Mg–OH bond break and H 2 O radiolysis. Framework break seems more important, Mg–OH bond break and H 2 O radiolysis are secondary. It seems talc exhibits poor stability to radiation. Clay matrix mightn’t ensure the effectiveness of disposal project, the effect of nuclear accident to environment can be serious.