Abstract: With the modified sodium bentonite from Gaomiaozi, Inner Mogolia, as the object of study, the distribution coefficients of ¹³⁷Cs in its original form and froms of, being gamma-ray irradiated and gamma-ray irradiation-thermal sequential aging were measured separately using batch method. Results show that gamma-ray irradiation helps improve the ¹³⁷Cs absorbtion of the sodium bentonite under the experimental conditions in this study. Comparing with the modified sodium bentonite, the absorbtion of sodium bentonite experiencing gamma rays irradiation has an increment in the range of 30.1% to 39.4%. The results also show that compared with gamma rays irradiation, gamma rays irradiation-thermal sequential aging can make the absorption capacity of ¹³⁷Cs on modified sodium bentonite further intensified,mean increment reaches up to 16%.

Key words: modified sodium bentonite, γ-rays irradiation, γ-rays irradiation-thermal sequential aging, distribution coefficient